Blog
News, research and guides
348 articles from our editorial and science team.
GuidesUterine Fibroids: Symptoms and Treatment — from Watchful Waiting to Surgery
Uterine fibroids are the most common benign tumor of the female reproductive organs — estimates range from a few percent to over 70%, depending on the diagnostic method and age, and for many women they remain symptom-free for life. For others they cause heavy, multi-day bleeding, pain, and pelvic pressure that genuinely reduce quality of life. We explain how the different fibroid types differ, when watchful waiting is enough, and when it's worth considering drug therapy, myomectomy, hysterectomy, or uterine artery embolization (UFE).
PZdr Piotr Zieliński14 min
September 16, 2026
GuidesOvarian Cysts: When to Worry, and When to Just Keep Watching?
A cyst on the ovary found on ultrasound triggers worry almost automatically, even though the vast majority of such findings are harmless, functional cysts that disappear on their own within a few cycles. The problem is that the same word also covers rarer pathological changes that need monitoring or treatment, and — very rarely — acute situations like ovarian torsion that require immediate help. We explain how the different cyst types differ, which symptoms are normal, and which should prompt an urgent visit.
PZdr Piotr Zieliński13 min
September 16, 2026
GuidesFibrocystic Breast Changes: Causes and Management
Tenderness, lumpiness, and a "grainy" feeling in the breasts just before a period affects up to 90% of women at some point in their lives — a phenomenon common enough that medicine long ago stopped calling it a disease. Fibrocystic breast changes (today more often called simply fibrocystic changes rather than "fibrocystic breast disease") don't themselves raise breast-cancer risk, but they can be a source of real discomfort and anxiety, especially when a new, palpable lump appears. We explain the hormonal mechanism behind these changes, what actually helps ease symptoms versus what's a myth, and when a breast lump needs urgent evaluation.
PZdr Piotr Zieliński13 min
September 16, 2026
GuidesPregnancy Nutrition: What to Eat and What to Avoid
"Eating for two" is one of the most misleading phrases in pregnancy nutrition — actual calorie needs rise far less than the saying implies, while the need for specific nutrients rises considerably. Folate, iron, iodine, choline, and DHA have documented effects on a baby's development, and a handful of specific food categories — raw fish, unpasteurized cheese, high-mercury fish, alcohol — carry real, well-documented risk. We check what ACOG, FDA/EPA guidance, and specific clinical studies actually say.
MNMichał Nowak14 min
September 16, 2026
GuidesBenign Prostatic Hyperplasia: Symptoms and Treatment Step by Step
Benign prostatic hyperplasia (BPH) affects most men to some degree after age fifty, with the proportion rising with each passing decade. Symptoms — more frequent urination, nocturia, a weaker stream — are often dismissed as a "natural part of aging," even though a wide range of effective treatments is now available: from lifestyle changes, through first- and second-line medications, to minimally invasive procedures and classic surgery. We explain how diagnosis works, how the different drug classes differ, and when it's worth considering procedural treatment.
PZdr Piotr Zieliński14 min
September 16, 2026
GuidesTelogen Effluvium or Androgenetic Alopecia? How to Tell Different Types of Hair Loss Apart
You suddenly notice more hair on your brush and in the shower drain — and the immediate question is whether this is a temporary episode that will resolve on its own, or the start of permanent, progressive hair loss. Telogen effluvium and androgenetic alopecia are two completely different phenomena, with different courses, different prognoses, and different treatments, but they're often confused because both present as the same thing — more hair loss than usual. We explain how to tell them apart by pattern, timing, and trigger, and when both types can occur at the same time.
PZdr Piotr Zieliński14 min
September 16, 2026
GuidesPanic Attacks: Symptoms and How to Cope
A panic attack can trigger physical symptoms so intense — a racing heart, breathlessness, chest pain — that many people end up in the emergency room convinced they're having a heart attack. This isn't "overblown nervousness": it's a specific, well-documented condition with clear diagnostic criteria, real in-the-moment coping methods, and effective long-term treatment. We explain how to tell a panic attack apart from a life-threatening condition, what actually helps during an episode, and which treatments have the strongest research support.
MWdr Marek Wójcik14 min
September 16, 2026
GuidesSocial Anxiety Disorder: Symptoms and Treatment
The line between shyness and social anxiety (social phobia) can be confusing, but in clinical practice it's fairly clear: it's about the degree of distress and the real impact on daily functioning, not just discomfort in social contact. This is one of the most common anxiety disorders, and also one of the better-researched in terms of treatment — a network meta-analysis of dozens of studies points specifically to which form of cognitive behavioral therapy works most strongly and how it compares with medication. We check what the data actually show.
MWdr Marek Wójcik13 min
September 16, 2026
GuidesBurnout: Symptoms and Recovery
Since 2019, burnout has had an official place in the WHO classification as an "occupational phenomenon" — not a disease, but a condition resulting from chronically unmanaged workplace stress, described by three specific dimensions: exhaustion, cynicism toward work, and a sense of reduced effectiveness. The practical problem is that burnout symptoms largely overlap with depression symptoms, which makes it harder to identify the right cause and choose the appropriate help. We check what the research actually shows about the mechanism of burnout, how to tell it apart from depression, and which recovery strategies have real confirmed effectiveness.
MWdr Marek Wójcik14 min
September 16, 2026
GuidesAdult Asthma: Symptoms, Triggers, and What Good Treatment Actually Looks Like
Asthma in adults is often mistaken for a chronic cough, a lingering allergy, or simply "being out of shape" — and even among people who already know they have it, many are still managed the way the disease was treated a decade ago, on the assumption that a rescue inhaler is enough. The latest Global Initiative for Asthma (GINA) guidance changed that approach fairly dramatically. We explain how inhaler types actually differ, why relying on a SABA "whenever needed" is now considered a mistake, and how to recognize when asthma isn't actually under control.
KLdr Katarzyna Lewandowska13 min
September 16, 2026
GuidesHay Fever: How to Actually Manage It
Hay fever is often treated as a minor spring-season inconvenience rather than a full-fledged health problem — yet for some people it can genuinely disrupt sleep, concentration, and daily functioning for several months a year. We explain the difference between intranasal and oral antihistamines, why intranasal steroids are today's first-choice treatment rather than "heavier artillery," and when allergen immunotherapy is worth considering as the only disease-modifying method rather than one that merely eases symptoms.
KLdr Katarzyna Lewandowska13 min
September 16, 2026
GuidesUlcerative Colitis: Symptoms, Diagnosis, and Treatment Step by Step
Ulcerative colitis (UC) is a chronic inflammatory bowel disease in which the immune system attacks the lining of the colon. The disease runs in cycles of flares and remission, and its diagnosis and treatment follow a clearly defined therapeutic ladder — from mesalamine, through steroids during flares, to biologic drugs. We explain what that path looks like in practice, how diagnosis works, and when symptoms should prompt urgent medical attention.
MNMichał Nowak14 min
September 16, 2026
GuidesCrohn's Disease: Symptoms, Complications, and Treatment Step by Step
Crohn's disease is a chronic inflammatory bowel disease that — unlike ulcerative colitis — can affect any part of the digestive tract, from mouth to anus, and attacks the full thickness of the bowel wall. That's exactly what drives the complications typical of Crohn's: strictures, fistulas, and abscesses, all rare in ulcerative colitis. We explain how to tell the two diseases apart, how diagnosis works, and how the modern treatment ladder is built.
MNMichał Nowak14 min
September 16, 2026
GuidesType 2 Diabetes: How Treatment Looks From Diagnosis — Step by Step
A diagnosis of type 2 diabetes usually raises more questions than get answered in a single visit: where to start, whether medication is needed right away, what HbA1c level to aim for. We explain what standard management actually looks like today after diagnosis — from lifestyle change, through metformin as the first-choice drug, to situations where further drugs are added to treatment — in line with current American Diabetes Association guidelines.
PZdr Piotr Zieliński13 min
September 16, 2026
GuidesPrediabetes: How to Reverse It Before It Becomes Type 2 Diabetes
Prediabetes likely affects several million adults, and most don't know they have it. It's also one of the few moments in the natural course of metabolic disease where the process is largely reversible — provided intervention comes early enough. The largest study on the topic, the American Diabetes Prevention Program, found that intensive lifestyle change cut the risk of developing type 2 diabetes by 58%, more effectively than metformin alone. Here's what the diagnosis actually means, which interventions have real research backing, and when medication enters the picture.
PZdr Piotr Zieliński13 min
September 16, 2026
GuidesVitiligo: Causes and Treatment — What Actually Works?
Acquired vitiligo affects about 1% of the world's population, and for decades it was treated mainly as a cosmetic issue that was hard to treat effectively. That's changing: we now understand the autoimmune mechanism behind melanocyte destruction far better, and in 2022 the first drug in history — ruxolitinib cream — showed documented repigmentation efficacy in large phase 3 trials. We explain what actually causes vitiligo, which treatments have real support from clinical trials, and what patients can realistically expect from therapy.
AKdr Anna Kowalczyk13 min
September 16, 2026
GuidesMelasma and Skin Hyperpigmentation: Evidence-Based Causes and Treatment
Melasma is one of the most stubborn types of skin hyperpigmentation — symmetrical, brown patches on the face that worsen with sun exposure and hormonal fluctuations, and that can come back even darker after poorly chosen treatment. We explain what actually triggers melasma, why sun protection is the foundation of every therapy, and which treatments — from hydroquinone to tranexamic acid — actually have real clinical evidence behind them.
AKdr Anna Kowalczyk13 min
September 16, 2026
GuidesSunscreen: How to Choose It and Does It Really Work
Sunscreen has something most cosmetics lack: randomized clinical trials showing a real reduction in photoaging and melanoma with regular use. The problem is that most people apply far too little to reach the SPF printed on the label. We explain what the SPF and PA numbers actually mean, how mineral filters differ from chemical ones, and how much cream you need to apply for the protection to actually work.
AKdr Anna Kowalczyk13 min
September 16, 2026
GuidesTennis Elbow: Causes and Treatment — Why Rest Alone Isn't Enough
Tennis elbow (lateral epicondylitis) rarely has anything to do with tennis — it most often affects people doing physical work, heavy computer-mouse users, or strength trainers. It isn't classic "inflammation" but a chronic, degenerative change in the tendon that responds poorly to rest alone and, surprisingly, poorly to steroid injections over the long run. We look at what the evidence actually shows about eccentric exercise, braces, and injections.
MNMichał Nowak13 min
September 16, 2026
GuidesAnterior Cruciate Ligament (ACL) Tear: Injury and Rehabilitation
For years, a torn anterior cruciate ligament (ACL) was treated as an injury that almost automatically called for surgery. The randomized KANON trial, following patients for 5 years, challenged that assumption: some people do just as well with rehabilitation alone, with delayed surgery available only if needed. We look at what the data actually show about choosing between surgical and conservative treatment, the phases of rehabilitation, and a safe return to sport.
MNMichał Nowak14 min
September 16, 2026
GuidesShin Splints (Medial Tibial Stress Syndrome): Causes and Prevention
Shin splints, known in the medical literature as medial tibial stress syndrome (MTSS), are one of the most common overuse injuries among runners and military recruits. Pain along the inner edge of the shin is often mistaken for a stress fracture — and the distinction matters clinically, because a wrong diagnosis means the wrong treatment. We look at what the research says about risk factors, prevention, and when shin pain is something more serious than overuse.
MNMichał Nowak12 min
September 16, 2026
GuidesDry Eye Syndrome: Causes and Treatment
Dry eye syndrome is one of the most common reasons for an eye-doctor visit — and one of those conditions whose scale is systematically underestimated, because many people treat burning, tired eyes as an unavoidable side effect of screen work. In reality there are far more causes, from natural aging to autoimmune diseases like Sjögren's syndrome, and treatment success depends heavily on correctly identifying the cause, not just relieving symptoms with artificial tears.
KLdr Katarzyna Lewandowska13 min
September 16, 2026
GuidesGout: Causes and Treatment
Gout is the most common inflammatory joint disease in adult men — and a disease whose treatment still runs into the same mistakes: treating only the acute flare without addressing the underlying cause, doses of urate-lowering drugs that are too low or titrated too slowly, and stopping therapy prematurely once the pain resolves. We look at what the American College of Rheumatology guidelines and major clinical trials actually show about treating a flare and long-term therapy.
MNMichał Nowak14 min
September 16, 2026
GuidesRheumatoid Arthritis: Symptoms, Causes, and How Treatment Works
Rheumatoid arthritis is an autoimmune disease in which the immune system attacks your own joints — and the later it's diagnosed, the harder it becomes to prevent permanent damage. The problem is that early RA symptoms are easy to mistake for osteoarthritis or plain fatigue. We explain how RA differs from osteoarthritis, what today's treatment ladder looks like — from disease-modifying drugs to biologics — and when to urgently see a rheumatologist.
AKdr Anna Kowalczyk14 min
September 16, 2026
GuidesThe Fasting-Mimicking Diet (FMD): What Is It and What Does the Research Actually Show?
The fasting-mimicking diet (FMD) is a five-day nutrition protocol designed by Valter Longo's team that aims to trigger effects in the body similar to full fasting, while still providing a limited amount of food. It gained wide attention through the commercial product ProLon, but behind the marketing there's also a real, if still limited, body of scientific literature. We explain how FMD differs from water fasting, which populations it has actually been studied in, and where the evidence is stronger versus where it's still an early stage of research.
AKdr Anna Kowalczyk13 min
September 16, 2026
GuidesPeptide Therapy: Overview and Safety — What's a Drug, and What's a Gray Market
"Peptides" has become a catch-all buzzword in biohacking covering both real, FDA-approved drugs and hundreds of substances sold online as "research use only" — with no oversight of quality, sterility, or dosing. This article pulls the two apart: we check which peptides actually made it through drug approval, which are circulating in a legal gray zone, and what real risk comes with the second group.
AKdr Anna Kowalczyk14 min
September 16, 2026
GuidesWhole-Body Cryotherapy: Does It Actually Work, or Is It Just a Pricier Cold Shower?
Cryotherapy chambers, where the temperature drops to -110°C or lower, promise faster recovery, less inflammation, and reduced muscle soreness after training — for a single session that can cost a fair amount of money. The latest meta-analyses, however, paint a more nuanced picture than wellness-industry marketing suggests: a real anti-inflammatory effect does exist, but the evidence for reducing muscle soreness right after exercise is much weaker than commonly assumed.
AKdr Anna Kowalczyk13 min
September 16, 2026
GuidesMercury in Fish: Should You Worry? What the Research and Official Guidelines Say
Fish are one of the best-documented sources of omega-3 fatty acids in the human diet, but also the main source of dietary exposure to methylmercury. Rather than a choice between "eat fish" and "avoid fish," official FDA and EPA guidelines offer something more precise: which species to eat without worry, and which to avoid — especially during pregnancy. We check where these recommendations come from and why two large cohort studies produced seemingly contradictory results.
AKdr Anna Kowalczyk13 min
September 16, 2026
GuidesPFAS — "Forever Chemicals": Should We Be Worried?
PFAS, or per- and polyfluoroalkyl substances, are known as "forever chemicals" because they practically don't break down in the environment or in the human body. In 2024, the US EPA introduced the first-ever binding limits for PFAS in drinking water — a decision based on decades of research, including one of the largest epidemiological studies of an industrial population ever conducted anywhere in the world. We check what's actually linked to PFAS exposure, what remains speculation, and what practical steps can realistically reduce exposure.
AKdr Anna Kowalczyk14 min
September 16, 2026
GuidesMicronutrient Deficiencies: The Most Common Symptoms — A Practical Guide to Five Usual Suspects
Chronic fatigue, trouble concentrating, muscle cramps, or hair loss have dozens of possible causes — but five micronutrient deficiencies account for a surprisingly large share of such symptoms in the general population. This article is a practical guide to which deficiency is worth suspecting given which symptoms — not so you can diagnose yourself, but so you know exactly what to ask your doctor and which blood test to request first.
MNMichał Nowak14 min
September 16, 2026
GuidesSciatica: Causes and Evidence-Based Treatment
Sciatica — a burning pain that radiates from the lower back down the leg along the path of the sciatic nerve — is one of the most common reasons people see a doctor, and one of the most frequently mismanaged pain conditions. For decades the standard advice was bed rest; today we know that approach doesn't just fail to help, it can actively hurt recovery. We check what the research actually shows about disc herniation, piriformis syndrome, anti-inflammatory drugs, and surgery — and which symptoms mean sciatica has stopped being a home-care issue and become a medical emergency.
MNMichał Nowak13 min
September 13, 2026
GuidesCarpal Tunnel Syndrome: Causes and Evidence-Based Treatment
Numbness, tingling, and pain in the thumb, index, and middle finger that worsen at night — that's the classic picture of carpal tunnel syndrome, one of the most common compression neuropathies. We check what actually causes this condition, why obesity and hypothyroidism raise the risk more than you might expect, and what a randomized trial comparing wrist splinting with surgery actually found — including when a nerve conduction study is genuinely needed and when a clinical diagnosis is enough.
MNMichał Nowak12 min
September 13, 2026
GuidesDizziness: Causes and When to Worry
Dizziness is one of the most ambiguous symptoms in medicine — in one person it means benign BPPV that resolves after a few physical therapy maneuvers, in another it can be the first sign of a brainstem stroke. As a cardiologist, I look at this symptom primarily through the lens of the circulatory system — orthostatic hypotension, cardiac arrhythmias — but it's equally important to know when the problem goes beyond cardiology and needs urgent neurological or ENT evaluation. We check what actually distinguishes benign causes of dizziness from those requiring immediate hospital assessment.
KLdr Katarzyna Lewandowska13 min
September 13, 2026
GuidesSleep Apnea: Symptoms, Causes, and How Diagnosis Works
Loud snoring interrupted by silence, morning headaches, and daytime sleepiness despite what looks like a full night's sleep — obstructive sleep apnea is often dismissed for years, because most of its symptoms are noticed by a partner, not the patient. Yet untreated apnea isn't just about worse quality of life: it carries a measurably higher cardiovascular risk, confirmed in meta-analyses covering tens of thousands of people. Here's how to recognize the symptoms, what a sleep study actually involves, and what real treatment options exist beyond CPAP alone.
JWJulia Wiśniewska14 min
September 13, 2026
GuidesBruxism: Why We Grind Our Teeth and What Actually Helps
Clenching your jaw during the day at your desk and grinding your teeth at night — something you only learn about from a partner or a dentist — are two faces of the same phenomenon: bruxism. Stress and anxiety are the best-documented risk factor, but the list is longer, including certain antidepressants, alcohol, caffeine, and coexisting sleep apnea. We explain the mechanism, the consequences for teeth and the jaw joint, and what the evidence actually says about night guards and other treatments.
MWdr Marek Wójcik13 min
September 13, 2026
GuidesMaca Root, Libido, and Energy
Maca (Lepidium meyenii) is a Peruvian root from the cabbage family, eaten in the Andes for centuries as food and sold in the West for the past decade as a natural "aphrodisiac" and energy booster. A handful of small but genuinely conducted clinical trials actually do show an improvement in sexual desire with maca supplementation — and, interestingly, without any change in testosterone levels, one of the more curious and less well-known findings in this field. The second part of the marketing promise — "energy" — is far less documented, with evidence that is, in practice, almost entirely anecdotal.
MNMichał Nowak13 min
September 10, 2026
GuidesRhodiola for Fatigue and Stress
Chronic stress-related fatigue and professional burnout are among the most common reasons patients see a psychiatrist today, and rhodiola is one of the few adaptogens with studies specifically designed around this particular problem — not general "stress resistance," but measurable mental fatigue. We check what these studies actually show, where the evidence ends and overinterpretation begins, and for whom rhodiola may be a real element of support rather than a substitute for treatment.
MWdr Marek Wójcik14 min
September 10, 2026
GuidesBacopa Monnieri for Memory and Focus
Bacopa monnieri is one of the few plant nootropics for which a meta-analysis of randomized trials shows a specific, repeatable effect — but that effect covers a narrower range of cognitive functions than the popular "for memory and focus" slogan suggests. We check exactly which aspects of memory bacopa improves, why its effect on immediate focus is far less documented than on long-term recall, and why patience is key here.
JWJulia Wiśniewska13 min
September 10, 2026
GuidesCiticoline (CDP-Choline) and Concentration: What Does the Research Actually Show?
Citicoline is often marketed as an all-purpose nootropic for memory, mood, and focus at once. The evidence, however, is uneven — the most solidly documented effect isn't memory, but a narrower, more specific domain: psychomotor speed and attention. We check what studies on healthy teenagers and adults actually found, how much of that effect can be attributed to citicoline itself versus the caffeine present alongside it in some studies, and why it's worth knowing who funded a study before treating its result as final.
JWJulia Wiśniewska13 min
September 10, 2026
GuidesThe Carnivore Diet: Facts and Myths — What Does the Research Actually Say?
The carnivore diet (animal products only, zero plants) is one of the most radical dietary trends of recent years — surrounded by both enthusiastic accounts of vanishing digestive complaints and warnings about severe fiber and vitamin deficiency. The largest study to date covered more than 2,000 people, but relies entirely on self-report, with no control group — something experts critical of the study consider a significant limitation. We check what's actually known, where the data ends and anecdote begins, and what real risks come with a diet that has no room for even a single vegetable.
MNMichał Nowak14 min
September 10, 2026
GuidesSIBO — Small Intestinal Bacterial Overgrowth
SIBO (small intestinal bacterial overgrowth) is a condition in which bacteria that normally colonize the large intestine multiply excessively in the small intestine, where under normal conditions there are far fewer of them. The result is bloating, gas, abdominal pain, and diarrhea or constipation that's easy to mistake for irritable bowel syndrome — and indeed, research shows the two diagnoses overlap far more often than one might expect. The trouble is that the standard diagnostic tests for SIBO have real limitations, and the term itself is often used more broadly today than the evidence supports.
MNMichał Nowak13 min
September 10, 2026
GuidesLeaky Gut Syndrome — Is It a Real Diagnosis?
"Leaky gut" (leaky gut syndrome) is one of those terms that exist simultaneously in two very different worlds. In the scientific literature, increased intestinal permeability is a real, measurable physiological phenomenon, studied for decades and linked to several specific diseases. In the popular corners of the internet, "leaky gut syndrome" is often a standalone, all-encompassing diagnosis, made without testing and "treated" with expensive supplements. We check where one ends and the other begins.
AKdr Anna Kowalczyk13 min
September 10, 2026
GuidesHelicobacter pylori: Symptoms, Diagnosis, and Treatment of Infection
Helicobacter pylori is a bacterium that colonizes the stomach of nearly half the world's population, in most cases without symptoms. The problem is that in some infected people it leads to chronic inflammation of the stomach lining, peptic ulcer disease, and, in rare cases, gastric cancer — and rising antibiotic resistance means standard treatment increasingly fails. We check how to recognize an infection, when treatment actually reduces gastric cancer risk, and when antibiotic therapy "just in case" misses the point.
MNMichał Nowak14 min
September 10, 2026
GuidesMicroplastics in the Human Body: Should We Be Worried?
Over the past five years, scientists have found microplastics in blood, placenta, lungs, and even the brain. The headlines sound alarming, but the gap between "plastic particles were detected in tissue" and "plastic is harming us" is enormous and rarely explained clearly. We check what's actually known: where microplastics have been found, what the real, verified exposure sources are, what one large study linking them to cardiovascular risk actually showed, and why most of this science is still at the hypothesis stage rather than proven causation.
AKdr Anna Kowalczyk14 min
September 10, 2026
GuidesHyperbaric Oxygen Therapy — What It Is and Does It Work?
A hyperbaric chamber today conjures two entirely different worlds: a hospital ward treating carbon monoxide poisoning and non-healing wounds, and private wellness clinics where healthy people pay for sessions supposedly reversing aging and improving cognitive function. It's no accident these two pictures look so different — because the quality of evidence behind them differs too. We check where solid, well-documented medicine ends and preliminary, promising but still speculative science begins.
AKdr Anna Kowalczyk14 min
September 10, 2026
GuidesInfrared Sauna vs. Traditional Sauna: How Different Are They, Really?
The infrared sauna is marketed as a gentler, more convenient alternative to the traditional Finnish sauna — operating at a lower temperature, but supposedly delivering similar benefits. That's partly true, but the real story is more complex: both forms heat the body through completely different physical mechanisms, have very different depth and quality of evidence behind them, and one of the few areas where the infrared sauna has genuinely strong, randomized data concerns a narrow group of cardiac patients in Japan — not the general population looking for a biohacking edge.
KLdr Katarzyna Lewandowska13 min
September 10, 2026
GuidesSwimming as a Workout: What Are the Real Health Benefits?
Swimming is sometimes called the most complete form of physical activity — it engages nearly every muscle group, is gentle on the joints, and doesn't require high fitness to get started. One of the largest cohort studies in this field even suggests that swimmers have significantly lower all-cause mortality than runners, walkers, or sedentary people. We check what research actually confirms about swimming — for the cardiovascular system, joints, and mental health — and where the swimming community's enthusiasm runs ahead of the available evidence, particularly on bone density.
MNMichał Nowak13 min
September 10, 2026
GuidesMobility and Flexibility Training: Why Should You Add It to Your Workout Plan?
Mobility is often treated as an add-on to "real" training — something you do in the last five minutes of a session, if there's even time for it. Yet joint range of motion is one of those fitness parameters that deteriorates fastest without deliberate work on it, and its loss has real consequences: from worse resistance-training technique, through higher risk of overuse injury, to — in older adults — a documented link to falls. We check exactly what research says about mobility training, how it differs from ordinary stretching, and when stretching can actually do harm.
MNMichał Nowak13 min
September 10, 2026
GuidesFibromyalgia — What Actually Helps?
Fibromyalgia has long been described as a disease that "doesn't show up" on any standard blood test or scan — which for decades led some doctors to dismiss patients' symptoms, and patients on a frustrating journey between specialists in search of a diagnosis. Today we know it is a real, well-described disorder of pain processing in the central nervous system, not a figment of imagination or "nerves." There's no single pill that switches it off — but there is a solid set of interventions with real research support that, in practice, help most patients regain function, even if they don't eliminate pain entirely.
MWdr Marek Wójcik14 min
September 10, 2026
GuidesPlantar Fasciitis — Causes, Risk Factors, and What Actually Helps
A stabbing, burning heel pain with the first steps after getting out of bed is one of the most recognizable symptoms in orthopedics — and one of the most common causes of foot pain in adults. Plantar fasciitis is often mistakenly reduced to a "heel spur" and treated with methods of questionable effectiveness, while the evidence points to a much simpler, cheaper first-choice intervention. We check what actually raises the risk of this condition, which treatment methods have real support in research, and why popular steroid injections carry a risk that's rarely discussed openly.
MNMichał Nowak13 min
September 10, 2026
GuidesFrozen Shoulder — Symptoms, Causes, and What Effective Rehabilitation Looks Like
Frozen shoulder (adhesive capsulitis) can develop over months, starting with unremarkable pain and ending in a dramatic loss of shoulder mobility that makes even getting dressed or reaching for a wallet in a back pocket difficult. The popular belief that the problem will "go away on its own" within a year is, in light of newer research, an oversimplification — and the choice between physical therapy, a steroid injection, and an invasive procedure can be less obvious than popular guides suggest. We check what actually raises the risk of frozen shoulder, why it's so strongly linked to diabetes and thyroid disease, and which treatment methods have real support in research.
MNMichał Nowak14 min
September 10, 2026
GuidesPMDD — How Does It Differ from PMS?
Premenstrual syndrome (PMS) and premenstrual dysphoric disorder (PMDD) are often treated as the same thing, just at different intensities. That's a mistake — PMDD is a distinct diagnostic entity in the DSM-5, dominated not by bloating or breast tenderness, but by severe, cyclical mood symptoms: irritability bordering on explosiveness, deep sadness, anxiety, and a sense of losing control, severe enough to genuinely disrupt work and relationships for a dozen-plus days every month. We explain where this distinction comes from, what research shows about its biological basis, and why SSRIs — sometimes taken for only half the cycle — are the first-line treatment.
PZdr Piotr Zieliński13 min
September 10, 2026
GuidesDigital Eye Strain — How to Deal With It?
Burning, tired eyes by the end of a day at the screen, blurred vision after hours in a spreadsheet, a headache that shows up right when you close the laptop — it's not your imagination. Digital eye strain (computer vision syndrome) affects, according to meta-analyses, most regular screen users. The problem is that the most popular piece of advice — the 20-20-20 rule — rests on much weaker research support than its popularity would suggest. We check what actually happens to your eyes during screen work and which strategies have real evidence behind them.
JWJulia Wiśniewska13 min
September 10, 2026
GuidesGlaucoma — Risk Factors and Prevention
Glaucoma is one of the leading causes of irreversible blindness worldwide, yet most people who have it don't know it — the most common form gives no symptoms for years, until visual field loss becomes significant. There's no single test that predicts it with total certainty, but decades of epidemiological research and one of the most important clinical trials in ophthalmology — the Ocular Hypertension Treatment Study — have made it possible to describe fairly precisely who falls into a higher-risk group and how often it's worth getting checked. This article isn't a guide to treating glaucoma — we focus on risk factors and what an average reader can realistically do about prevention and early detection.
KLdr Katarzyna Lewandowska13 min
September 10, 2026
GuidesHalitosis — What Actually Causes Bad Breath
Bad breath is usually blamed on poor hygiene — but in the vast majority of cases, it isn't about brushing too rarely. Systematic reviews show that in 85-90% of cases the source of the problem sits in the mouth itself, and the single most common cause is bacterial coating on the back of the tongue, not gum disease or a bad diet. We check what's actually known about the causes of halitosis, how it's really diagnosed in clinical settings, and which interventions — tongue scraping, specific mouthwashes, probiotics — have real support in clinical trials, and which are mostly a promise printed on the packaging.
MNMichał Nowak13 min
September 10, 2026
GuidesBlack Seed — Nigella Sativa Oil and Its Properties
Black seed oil (Nigella sativa) is often marketed as a near cure-all — from immune support to fighting cancer. The reality is more restrained, though far from empty: several independent meta-analyses of randomized controlled trials show a real, if modest, effect on glycemic control in type 2 diabetes, lipid profile, and blood pressure. We check which claims are backed by clinical studies in humans and which remain at the test-tube or animal-model stage.
MNMichał Nowak13 min
September 10, 2026
GuidesRapamycin and Longevity: What Animal Studies and the First Human Trials Show
Rapamycin (sirolimus) is an immunosuppressant drug that has been used for more than 20 years after organ transplants, and it has simultaneously become one of the most studied candidates for an anti-aging drug. The reason is concrete: it is the only pharmacological intervention that consistently extends lifespan across independently repeated mouse studies. A growing number of people outside transplant clinics are seeking it out off-label, hoping for a similar effect in humans — even though evidence for that is still practically nonexistent, and the drug remains a real immunosuppressant with real side effects. We look at what animal studies have actually shown, what the first larger human trial (PEARL) has demonstrated so far, and where the line lies between promising science and premature self-medication.
AKdr Anna Kowalczyk14 min
September 9, 2026
GuidesSpermidine and Autophagy: What Animal Studies and Early Human Trials Actually Show
Spermidine is a natural polyamine present in every cell of our body, whose levels steadily decline with age. It's one of the few natural compounds with real, repeated mechanistic evidence of autophagy activation and a large observational study linking higher intake to lower mortality. But it's also a good example of how a promising result from a small human pilot trial (30 people) failed to hold up in a larger, better-designed trial (100 people) run by the same team. We take a close look at what each study actually showed, and where the limits of our current knowledge lie.
AKdr Anna Kowalczyk13 min
September 9, 2026
GuidesFisetin as a Senolytic: What the Mouse Study Showed and Where Human Research Stands Today
Fisetin is a flavonoid found in strawberries, apples, and onions that made longevity-media headlines in 2018 as the strongest of the studied natural senolytics — compounds that selectively clear senescent (aging) cells. The mouse result was genuinely strong: extended lifespan and reduced markers of aging across many tissues. The problem is that several years have passed since that study, and clinical trials in humans are still at the stage of pilot safety trials, not confirmed efficacy. We take a close look at what is actually known and what remains only a promising hypothesis.
AKdr Anna Kowalczyk13 min
September 9, 2026
GuidesQuercetin as a Senolytic: What the First Human Studies of the Dasatinib + Quercetin Combination Show
Quercetin, the same flavonoid we covered in an earlier article in the context of allergic rhinitis, plays an entirely different, far more experimental role in aging biology: as part of a combination with the oncology drug dasatinib (the "D+Q" protocol), studied as a senolytic — a substance that selectively clears senescent cells. This is the first pair of senolytic compounds for which real data have been published showing a reduction in senescent cells in humans, not just in animals. We take a close look at what these first clinical trials actually showed, what role quercetin itself actually plays in them, and where the limits of this evidence lie.
AKdr Anna Kowalczyk13 min
September 9, 2026
GuidesGinseng for Fatigue and Cognitive Function
Ginseng is one of the longest-used adaptogens in the world, and its effect on fatigue and cognitive function has been tested in dozens of clinical trials — with results that resist a one-line summary. In cancer patients with chronic fatigue, the effect is often clear and repeatable; in healthy people with everyday mental tiredness, the evidence is far weaker and inconsistent. We check what the clinical trials actually showed, where the effect is most credible, and where supplement marketing outruns the science.
MNMichał Nowak13 min
September 9, 2026
GuidesOMAD (One Meal a Day) — Is It Safe?
OMAD (One Meal A Day) is the most extreme popular variant of intermittent fasting — the entire day's calories and nutrients squeezed into a single, usually one-hour window. Unlike gentler protocols like 16:8, OMAD comes with its own distinct set of risks that rarely make it into popular write-ups: a higher risk of gallstones, large blood-sugar swings after one enormous meal, real difficulty covering protein and micronutrient needs, and open questions about where discipline ends and a disordered-eating pattern begins. We check what the research actually shows.
MNMichał Nowak13 min
September 9, 2026
Guides
Endocrine Disruptors — BPA and Phthalates: What Should We Actually Worry About?
Bisphenol A (BPA) and phthalates are everywhere — in plastic bottles, receipts, food packaging, cosmetics, and toys. For two decades scientists have warned these compounds may disrupt hormone function, and regulators in Europe and the US have reached strikingly different conclusions about how worried to be. We check what human studies actually show, where the evidence from animal models and high doses ends, and whether popular "BPA-free" alternatives are genuinely safer.
PZdr Piotr Zieliński14 min
September 9, 2026
Guides
10,000 Steps a Day — Myth or Proven Number?
The figure of 10,000 steps a day sounds like a research finding — round, specific, repeated by fitness apps and doctors alike. In reality it comes from a Japanese pedometer maker's 1965 marketing campaign, not from any clinical study. Only decades later did science actually examine how many daily steps are genuinely associated with lower mortality — and the answer is more nuanced, and for many people far more achievable, than the round number from a pedometer ad suggests.
MNMichał Nowak13 min
September 9, 2026
GuidesThyroid Nodules — When Should You Worry?
Thyroid nodules are surprisingly common — high-resolution ultrasound studies detect them in the majority of adults past a certain age, though they're far less often palpable on physical exam. Being told "you have a nodule on your thyroid," however, tends to trigger disproportionate anxiety, because in reality the vast majority of nodules are benign and never require treatment. We check what the American Thyroid Association guidelines and the TI-RADS system actually say about which nodules need further workup and which can safely be observed.
PZdr Piotr Zieliński14 min
September 9, 2026
GuidesHow to Lower Cortisol Naturally? 10 Ways That Actually Have Evidence
The internet is full of "7 ways to lower cortisol" lists that put diaphragmatic breathing next to a trendy supplement with zero research behind it, as if they belonged in the same category. We decided to do this differently: we checked which popular cortisol-lowering methods actually have studies measuring this hormone, rather than just a subjective sense of "feeling less stressed." The result is ten methods of varying evidence strength — with a clear distinction between what's solidly confirmed and what's still only preliminary.
MWdr Marek Wójcik19 min
September 7, 2026
GuidesHow to Improve Sleep Quality? 12 Ways Backed by Scientific Research
"Sleep hygiene" guides usually lump together tips of wildly different evidentiary weight — cognitive behavioral therapy for insomnia, backed by dozens of randomized trials, sits right next to advice like "sleep in a pitch-black room," for which the hard data is much thinner. We gathered twelve concrete ways to improve sleep quality and checked, for each one, what the research actually shows — clearly distinguishing the gold-standard treatment for insomnia from supportive, still-worthwhile-but-secondary habits.
JWJulia Wiśniewska21 min
September 7, 2026
GuidesHow to Increase Energy During the Day? 10 Science-Backed Ways
"Chronic fatigue" is one of the most common reasons people see a primary care doctor, and at the same time one of the worst-served topics in online guides — because alongside genuinely useful habits (sleep, movement, hydration), these guides regularly offer unverifiable promises of an "instant energy boost." We collected ten concrete ways to increase daytime energy that have real research behind them — including three that aren't a habit at all, but a signal to get a blood test before changing your lifestyle.
MNMichał Nowak18 min
September 7, 2026
GuidesHow to Improve Insulin Sensitivity? 10 Ways Backed by Research
Insulin resistance rarely gives clear symptoms before it progresses into prediabetes or type 2 diabetes — and the internet is full of advice like "drink apple cider vinegar and eat cinnamon and your blood sugar will sort itself out." Some of that advice has real, if modest, research support; other parts are single, overhyped findings. We gathered ten ways to improve insulin sensitivity with genuine scientific documentation, clearly separating what's strongly proven from what's still promising but preliminary.
MNMichał Nowak19 min
September 7, 2026
GuidesHow to Lower LDL Cholesterol Naturally? 10 Effective Ways Backed by Research
Elevated LDL cholesterol rarely hurts and rarely gives symptoms — we usually find out about it by chance, from a lipid panel result. In response, the internet offers dozens of "natural ways to lower cholesterol," some backed by solid randomized-trial meta-analyses, and others — as we've shown in our own dedicated tests — that simply don't work the way popular opinion claims. We gathered ten ways with real scientific documentation, with a clear assessment of how much LDL reduction you can realistically expect from each.
KLdr Katarzyna Lewandowska18 min
September 7, 2026
GuidesHow to Lower Triglycerides? 10 Ways That Actually Work
Triglycerides are the most "lifestyle-reactive" parameter on a lipid panel — unlike LDL, which changes slowly and moderately, triglyceride levels can drop (or rise) noticeably within a few weeks in response to diet, alcohol, or physical activity. That's good news for someone with an elevated result — but it's also fertile ground for popular oversimplifications. We gathered ten ways to lower triglycerides with real scientific documentation, clearly distinguishing which give a large, fast effect and which are a valuable but slower addition.
KLdr Katarzyna Lewandowska18 min
September 7, 2026
GuidesHow to Increase VO2 Max? 10 Evidence-Based Ways to Improve Your Fitness
VO2 max — the maximum amount of oxygen the body can take up during exercise — is one of the strongest, most consistent predictors of all-cause mortality among routinely measurable health markers. The internet is full of shortcuts on how to raise it: from the cult "zone 2 vs. HIIT" debate, through supplements of questionable value, to advice that confuses an acute physiological effect with a long-term adaptation. We gathered ten ways that actually have research backing — with an honest distinction between what's well documented and what's still preliminary.
MNMichał Nowak19 min
September 7, 2026
GuidesHow to Boost Your Metabolism? 10 Ways With Real Scientific Backing
"Boosting your metabolism" is one of the most overused phrases in the fitness and supplement industry — promised by everything from green tea to drinking cold water, often without mentioning how small most of these effects actually are. We checked ten strategies that genuinely have research support, honestly separating the ones with a real, if modest, effect on energy expenditure from the ones that are marginal at best.
MNMichał Nowak18 min
September 7, 2026
GuidesHow to Increase Strength After 40? 10 Ways Backed by Research
After 40, the loss of muscle mass and strength accelerates — a process called sarcopenia that, left unaddressed, progresses quietly for decades until it starts limiting everyday function. The good news: it's one of the few aging processes that can genuinely be reversed, not just slowed, if you reach for methods that are actually backed by research — not just another supplement from an ad.
MNMichał Nowak20 min
September 7, 2026
GuidesHow to Build Muscle After 40? 10 Rules That Actually Matter
Once you hit 40, people start talking about sarcopenia, falling testosterone, and "anabolic resistance" — and it's easy to believe that building muscle past this age is largely a losing battle against biology. That's not true. The mechanisms that make muscle grow — mechanical tension, protein availability, recovery — work exactly the same after 40 as they did after 25, just with a slightly smaller margin for error. This article collects 10 rules that actually hold up in the research — from how much protein you really need, through training frequency and volume, to the role of sleep and hormonal context — and is honest about which of them have strong evidence and which are reasonable extrapolations from limited data.
PZdr Piotr Zieliński19 min
September 7, 2026
GuidesHow to Lose Belly Fat? 10 Ways Backed by Research
Let's start with something popular guides prefer to stay quiet about: you can't "spot-burn" fat from your belly with crunches alone or a special "love handle" diet. Physiology doesn't allow for it — the body mobilizes fat from across the whole body according to an individual, largely genetically determined pattern, not from wherever you happen to be exercising. The good news is that visceral fat — the type that accumulates around the internal organs of the abdominal cavity, the metabolically most harmful kind of fat tissue — responds to certain interventions more strongly than subcutaneous fat elsewhere on the body. This article collects 10 ways to reduce belly fat that have real, verified research backing — without promises of spot-burning fat from one specific place.
MNMichał Nowak20 min
September 7, 2026
GuidesHow to Reduce Appetite Naturally? 10 Ways That Actually Help Control Hunger
Hunger and appetite aren't a matter of "willpower" — they're a complex, hormonally driven system in which leptin and ghrelin, sleep, meal composition, and stress levels all interact to decide whether you'll reach for a second helping. Popular advice like "just eat less" ignores this physiology, which is exactly why it so often fails. This article gathers 10 ways to naturally reduce appetite that have real, verified support in experimental research — with a clear distinction between effects that are large and solid, and those that are real but modest in numbers.
MNMichał Nowak19 min
September 7, 2026
GuidesHow to Improve Recovery After Training? 10 Ways Backed by Research
Recovery determines whether training actually translates into progress or just accumulating fatigue. The problem is the internet is full of contradictory advice — some tell you to ice-bath after every session, others sell 'recovery' supplements with zero evidence behind them. We go through 10 concrete ways, checking what the research actually shows for each one versus what's just repeated gym-floor lore.
JWJulia Wiśniewska19 min
September 7, 2026
GuidesHow to Increase Testosterone After 40? 10 Ways Worth Trying
If you're over 40 and looking for concrete actions rather than another explanation of what hypogonadism is, this article is for you. Instead of a supplement ranking, we go through 10 things you can actually start doing this week, clearly distinguishing which have strong research backing and which are worth trying but without a guaranteed effect.
PZdr Piotr Zieliński20 min
September 7, 2026
GuidesHow to Lower Blood Pressure Naturally? 10 Evidence-Based Ways
High blood pressure is often called the "silent killer" — it can progress for years without symptoms, while remaining one of the strongest, largely modifiable risk factors for stroke and heart attack. The internet is full of "natural" blood pressure advice, some of it backed by solid clinical trials, some of it unverifiable marketing. We collected ten concrete, natural ways to lower blood pressure, with real numbers from meta-analyses and randomized trials wherever those numbers exist — and an honest note on where the evidence is weaker.
KLdr Katarzyna Lewandowska19 min
September 7, 2026
GuidesHow to Raise HDL Cholesterol? 8 Ways Backed by Real Evidence
HDL is often called "good cholesterol," and the internet is full of advice on raising it — from supplements to drastic diets. The problem is that some of these methods really do raise the HDL number on your bloodwork, yet don't translate into lower risk of heart attack or stroke. We check eight concrete, researched ways to raise HDL — and honestly flag which of them also have evidence for real clinical benefit, and which simply move a number.
KLdr Katarzyna Lewandowska18 min
September 7, 2026
GuidesHow to Improve Heart Health Naturally? 12 Ways Backed by Research
Heart health rarely breaks down because of one bad decision, and it rarely improves because of one good one — it's the sum of dozens of everyday factors, some backed by large randomized trials and some still surrounded by popular oversimplification. We gathered twelve ways to improve cardiovascular health with real scientific documentation — from cholesterol and blood pressure to sleep and stress to quitting smoking — clearly separating what's strongly proven from what's still preliminary.
KLdr Katarzyna Lewandowska21 min
September 7, 2026
GuidesHow to Slow Down Aging? 10 Ways With the Best Scientific Evidence
The "longevity biohacking" market is growing faster than the number of large clinical trials that actually confirm the effectiveness of the methods being sold. We've gathered ten ways to slow down aging, clearly separating, for each one, what's confirmed in human studies from what, for now, is known mainly from animal models — because that distinction, more often skipped than emphasized, is the key to telling real science apart from marketing.
AKdr Anna Kowalczyk20 min
September 7, 2026
GuidesBeefsteak Fungus – How to Cook It? 5 Best Ways to Prepare This Unusual Mushroom
Beefsteak fungus doesn't resemble any other mushroom in the kitchen — not in looks, and not in how you cook it. Its tangy flavor and meaty, fibrous texture mean some classic mushroom recipes simply don't work for it, and some techniques that work beautifully with button mushrooms or porcini actually ruin the effect here. We've gathered five ways to prepare it that genuinely bring out its best qualities — along with the tools you need, common mistakes, and how to store the finished dish.
MNMichał Nowak14 min
September 6, 2026
GuidesBeefsteak Fungus – Can You Eat It? Edibility, Taste, and How to Prepare It
The sight of a sliced beefsteak fungus can be off-putting — its red, 'bleeding' flesh looks more like raw meat than any other forest mushroom. The answer to the edibility question is simple: yes, you can eat it. Things get more interesting once you ask how it actually tastes, how that changes with the age of the fruiting body and the way it's prepared, and whether it's even worth trying raw.
MNMichał Nowak13 min
September 6, 2026
GuidesBeefsteak Fungus in the Kitchen – What to Make With a Mushroom That Looks Like Bloody Meat?
Already have a few beefsteak fungus fruiting bodies in your basket and wondering exactly what to cook with them? This mushroom pairs well with other bold flavors — eggs, cheese, red wine, or roasted root vegetables. We've gathered dish ideas that genuinely play to its strengths — acidity and meaty texture — along with tips on what to pair it with, what to avoid, and what to do if you've foraged more than you can eat right away.
MNMichał Nowak14 min
September 6, 2026
GuidesBeefsteak Fungus in Cream Sauce — Step-by-Step Recipe
Braising in a sauce is the most 'forgiving' way to cook beefsteak fungus — it tones down the mushroom's characteristic sourness and softens its fibrous texture, resulting in a dish that's approachable even for people unsure whether they'll like this unusual species. Below is a simple recipe for beefsteak fungus braised in a cream-and-herb sauce, step by step, along with notes on ingredients, common mistakes, and serving suggestions.
MNMichał Nowak12 min
September 6, 2026
GuidesBeefsteak Fungus — Where Does It Grow, When to Look for It, and How to Identify It?
Beefsteak fungus doesn't grow just anywhere or at just any time of year — it's a species tied almost exclusively to one kind of tree and a narrow window in the calendar. That predictability, combined with a strikingly distinctive appearance, makes it one of the safer forest mushrooms to identify on your own — as long as you know what to look for, what gear to bring, and what to expect at each stage of the fruiting body's growth.
MNMichał Nowak14 min
September 6, 2026
GuidesMilk Thistle and Liver Health: What Does the Research Actually Show?
Milk thistle — or more precisely, the silymarin it contains — is one of the best-selling "liver" supplements in the world, marketed as natural protection against alcohol, medication, and fatty food. The evidence is far more mixed than the label suggests: silymarin lowers liver enzymes in meta-analyses of nonalcoholic fatty liver disease, yet in one of the best-designed trials on chronic hepatitis C, even high doses performed no better than placebo, and a Cochrane review found no confirmed effect on mortality in high-quality trials.
MNMichał Nowak13 min
September 4, 2026
GuidesGinkgo Biloba, Memory, and Circulation: What Do Large Trials Show?
The ginkgo tree is one of the oldest living tree species on Earth and one of the best-selling "nootropics" on the market, marketed as boosting memory, focus, and circulation. Large, multi-year clinical trials paint a surprisingly split picture: in healthy people and for dementia prevention, rigorous trials found no effect, while in patients with already-diagnosed cognitive impairment, used alongside standard treatment, it shows a measurable, if modest, improvement.
JWJulia Wiśniewska14 min
September 4, 2026
GuidesL-Carnitine and Fat Burning: Does the "Fat-to-Mitochondria Transporter" Actually Work?
L-carnitine has been sold for decades as a "fat burner" — a substance said to transport fat directly into mitochondria to be burned for energy. The biochemical mechanism is real, but a well-designed trial combining carnitine with aerobic training in women found no difference in fat loss versus placebo, while a meta-analysis of 37 trials shows only a modest, if repeatable, effect on body weight. We check what the data actually confirm versus what's just a logical but unproven marketing hypothesis.
MNMichał Nowak13 min
September 4, 2026
GuidesTongkat Ali and Testosterone: What Does the Research Show About This Popular "Booster"?
Tongkat Ali (Eurycoma longifolia), also known as "Malaysian ginseng," is one of the most promising natural "testosterone boosters" in supplementation — and one of the few backed by actual human trials rather than just animal models. A randomized trial in aging men showed a significant testosterone increase at a 200 mg daily dose, and a trial in stressed subjects recorded a 37% testosterone increase alongside a drop in cortisol. A meta-analysis confirms the direction of the effect, but rests on just five trials — we check how far these results can be generalized.
PZdr Piotr Zieliński13 min
September 4, 2026
GuidesDHEA After 40: Does Supplementing the "Youth Hormone" Make Sense?
DHEA (dehydroepiandrosterone) is a hormone produced by the adrenal glands whose level steadily declines from around age 25 — by age 70 it can be as much as 80% lower than in youth. This decline has made DHEA one of the most commonly supplemented "youth hormones" in the United States, where it's sold over the counter. But the largest, two-year randomized trial, published in the New England Journal of Medicine, found no evidence that supplementation restores muscle strength, improves body composition, or improves insulin sensitivity in aging men and women. We check where the evidence actually ends and the marketing begins.
PZdr Piotr Zieliński14 min
September 4, 2026
GuidesSemaglutide (Ozempic, Wegovy): What Do the Trials Actually Show About Side Effects?
Semaglutide, sold as Ozempic (diabetes) and Wegovy (weight loss), became within a few years one of the most prescribed and most talked-about drugs in the world. The promise — double-digit percentage weight loss without a restrictive diet — is backed by solid registration trials. Far less discussed is what those same trials showed on the other side of the ledger: who tolerates the drug poorly, what rare but serious complications large database analyses have flagged, and why part of the lost body weight isn't just fat.
PZdr Piotr Zieliński14 min
September 4, 2026
GuidesHMB and Muscle Loss: When Does This Supplement Actually Make Sense?
HMB (β-hydroxy β-methylbutyrate), a leucine metabolite, is often marketed as a universal muscle-protecting supplement — for athletes building mass and seniors worried about sarcopenia alike. The research shows a clear split: in healthy, regularly training young adults the effect is negligible, while in strongly catabolic situations — immobilization, old age, illness — the evidence for muscle protection is considerably stronger. This distinction gets lost in most marketing material.
MNMichał Nowak13 min
September 4, 2026
GuidesGlycine and Sleep Quality: What Does the Research on This Simple Amino Acid Show?
Glycine is the simplest of the protein-building amino acids — and, as a handful of small but consistent studies from Japan show, taken at a 3g dose before bed it may shorten time to fall asleep, improve subjective sleep quality, and reduce next-day sleepiness. This topic is regularly confused with a completely different question: choosing between magnesium glycinate and magnesium citrate. Here we're talking about something else entirely — glycine itself, taken as a free amino acid, independent of any mineral salt.
JWJulia Wiśniewska12 min
September 4, 2026
GuidesIodine and the Thyroid: Why Are Both Deficiency and Excess Risky?
Iodine is the only element the body uses for almost exactly one purpose: building thyroid hormones. That makes the relationship between iodine intake and thyroid function non-linear — both clear deficiency and chronic excess raise the risk of thyroid disorders, though through different mechanisms. A large cohort study from China and an analysis of British pregnant women show two different sides of the same problem, and popular seaweed supplements are often a source of iodine doses far exceeding what's been tested as safe.
PZdr Piotr Zieliński13 min
September 4, 2026
GuidesCeliac Disease vs. Non-Celiac Gluten Sensitivity: How Do They Differ and Get Diagnosed?
"Gluten intolerance" is a term that in practice covers two completely different phenomena: celiac disease — an autoimmune condition with a clear diagnostic test, which likely affects over a million undiagnosed people in the US — and non-celiac gluten sensitivity, whose existence as a reaction specifically to gluten was undermined by the same research team's own follow-up study. This is one of the rare cases in medicine where science openly corrected itself within two years.
MNMichał Nowak14 min
September 4, 2026
GuidesHistamine Intolerance: Symptoms, Causes, and the Low-Histamine Diet in Practice
Headaches after red wine, hives after aged cheese, diarrhea after tomatoes — more and more people are linking such symptoms to "histamine intolerance." It's a real clinical phenomenon, tied to a deficiency in the gut enzyme that breaks down histamine, but it's also one of the most over-diagnosed and poorly defined conditions in modern nutrition. We check what research on the low-histamine diet and DAO supplementation actually shows, and where the evidence ends and the popular narrative begins.
MNMichał Nowak13 min
September 4, 2026
GuidesFinasteride and Dutasteride for Male Pattern Hair Loss: Efficacy, Side Effects, and the Post-Finasteride Syndrome Debate
Finasteride has been, for nearly three decades, the best-studied drug for male pattern hair loss, and dutasteride is often marketed as its stronger successor. Both block the enzyme that converts testosterone into DHT — and both carry a risk of sexual side effects that a small subset of patients describe as persisting even after stopping the drug. We check what large clinical trials and meta-analyses actually show — without downplaying the controversy around so-called post-finasteride syndrome, but also without overstating it.
PZdr Piotr Zieliński14 min
September 4, 2026
GuidesBPC-157: What Is Actually Known About the "Regenerative Peptide" — and What Isn't
BPC-157 is often described online as a near-miraculous peptide for tendon, ligament, and joint injuries — regenerating tissue where other methods fail. The problem is that almost this entire reputation rests on rodent studies. Clinical data in humans is extremely limited, the substance isn't approved by any drug agency, and in many countries it's sold in a legal gray area as a "research compound" rather than a drug or supplement. This article is deliberately skeptical — because the evidence that actually exists deserves skepticism.
AKdr Anna Kowalczyk13 min
September 4, 2026
GuidesContinuous Glucose Monitoring (CGM) for Healthy People: Biohacking Trend or a Genuinely Useful Tool?
Continuous glucose monitoring (CGM) systems, originally designed for diabetics, have in recent years become a popular biohacking gadget among people without diabetes — worn to 'optimize diet' based on real-time glucose curves. We check what studies on glycemic patterns in healthy people actually show, whether interpreting individual spikes makes clinical sense, and where useful information ends and unnecessary anxiety about normal physiological fluctuations begins.
KLdr Katarzyna Lewandowska13 min
September 4, 2026
GuidesContrast Therapy (Alternating Hot and Cold) and Recovery — What the Studies Show
Alternating cold and hot water immersion is one of the oldest recovery practices in sport, now repopularized in biohacking as a way to speed up recovery after training. It's something different from cold alone, though — we've already covered cold water immersion and immunity and cold water after training and muscle gains separately. This time we check what happens in the body when cold and heat alternate, and whether this combination actually offers something more than cryotherapy alone.
AKdr Anna Kowalczyk12 min
September 4, 2026
GuidesGrounding (Earthing): Does the Science Actually Back It Up?
Walking barefoot on grass, grounding mats for sleep, conductive sheets — grounding (earthing) promises lower cortisol, better sleep, and reduced inflammation through "absorbing electrons from the ground." The problem is that nearly all the literature on this topic comes from the same small group of authors financially tied to companies selling grounding products. We check what these studies actually show, how large their methodological limitations are, and why a much bigger dose of skepticism than the marketing suggests is warranted.
AKdr Anna Kowalczyk13 min
September 4, 2026
GuidesBlue Light Blocking Glasses: Do They Actually Improve Sleep?
Amber-tinted glasses worn in the evening in front of a screen promise better sleep, less eye strain, and a healthier circadian rhythm. A handful of small studies do show promising results — but the largest, most rigorous review, a Cochrane analysis of 17 randomized trials, concluded that blue-light blocking glasses probably don't meaningfully change eye strain or sleep quality in the general population. We check where these two pictures diverge, and why that's not a contradiction so much as a question of who they might actually help, and under what conditions.
JWJulia Wiśniewska12 min
September 4, 2026
GuidesWhey vs. Casein Protein: Which Should You Actually Choose?
Whey and casein come from the same milk, but have completely different digestion kinetics — one acts like a fast injection of amino acids, the other like a slow, multi-hour release. This isn't a question of which protein is "better" in some general sense, but which one fits a specific situation better: right after training, during a long gap between meals, or before bed. We check what the research on digestion speed, muscle protein synthesis, and satiety of both proteins actually shows.
MNMichał Nowak12 min
September 4, 2026
GuidesSodium Bicarbonate and Exercise Performance: Does Baking Soda Actually Work?
Sodium bicarbonate (plain baking soda) is one of the few ergogenic supplements backed by dozens of studies and a meta-analysis spanning nearly 60 papers. The mechanism — buffering the hydrogen ions produced during intense anaerobic exercise — is well understood, and the effect is real, though small and limited to a specific type of effort. The practical problem isn't efficacy but tolerance: the dose that works ergogenically causes noticeable gastrointestinal distress in many people. We check who it's worth it for and how to minimize the risk of side effects.
MNMichał Nowak12 min
September 4, 2026
GuidesSpirulina and Chlorella — Superfood or Well-Packaged Marketing?
Spirulina and chlorella are cyanobacteria and algae sold under slogans like "complete protein," "more iron than spinach," and "natural heavy-metal detox." Some of these claims have real backing in research — others are honest at the level of raw chemical composition but misleading in the context of a typical supplement serving. On top of that there's a practical problem marketing stays quiet about: some products on the market have repeatedly been found contaminated with cyanobacterial toxins or pharmaceutical residues. We check point by point which of these claims hold up and which don't.
AKdr Anna Kowalczyk13 min
September 4, 2026
GuidesAstaxanthin for Skin and Eye Health: What Do Clinical Trials Show?
Astaxanthin, a red carotenoid from Haematococcus pluvialis algae, is marketed as a universal "super-antioxidant" for skin, eyes, and fatigue. A handful of small but real clinical trials do show concrete, measurable effects — improved skin moisture after UV exposure and protected visual acuity after screen work, but only in a specific age group. We check exactly what these trials showed, and what we still don't know.
AKdr Anna Kowalczyk13 min
September 4, 2026
GuidesCoenzyme Q10 for Fertility and Heart Health: What Do Clinical Trials Show?
Coenzyme Q10 is most often associated with easing statin-related muscle pain, but that's only a fragment of its clinical story. In heart failure, the large randomized Q-SYMBIO trial showed a real drop in mortality, and in male infertility, meta-analyses of randomized trials point to improved semen parameters and testosterone levels. We check exactly what these studies showed and how strong this evidence really is.
KLdr Katarzyna Lewandowska14 min
September 4, 2026
GuidesIron-Deficiency Anemia: Symptoms, Diagnosis, and What Happens Before Anemia Appears
Iron-deficiency anemia is the most common cause of anemia worldwide, affecting, according to the latest global burden of disease estimates, hundreds of millions of women. The problem is that the symptoms — fatigue, breathlessness, poor concentration — are vague enough to easily blame on stress, lack of sleep, or "just the season." We explain how iron deficiency is actually diagnosed, why a blood count alone may not be enough, and what research shows about the reversibility of symptoms.
MNMichał Nowak14 min
September 4, 2026
GuidesPerimenopause and Weight Gain: What Does the 21-Year SWAN Study Show?
"I gained weight around menopause and nothing works" is one of the most repeated complaints from women in their forties and beyond. The largest long-term cohort study on the topic — the Study of Women's Health Across the Nation (SWAN) — shows this isn't just perception: the rate of fat gain genuinely doubles at a specific, predictable point in the menopause transition. We check exactly what changes, why hormone therapy isn't a simple fix, and what intervention studies actually show.
PZdr Piotr Zieliński14 min
September 4, 2026
GuidesLow Libido in Women: Hormonal, Psychological, and Medication-Related Causes
Reduced sexual desire is the most commonly reported sexual problem in women, and its frequency rises during the perimenopausal period. The problem is that the causes are often layered — hormonal, psychological, medication-related, or relationship-based — and treating just one without recognizing the others rarely brings full improvement. We check what meta-analyses show about the scale of the problem, testosterone therapy, and the effect of antidepressants on sexual desire.
PZdr Piotr Zieliński14 min
September 4, 2026
GuidesPDE5 Inhibitors (Viagra, Cialis): How They Really Work and Who They're Safe For
Sildenafil (Viagra) and tadalafil (Cialis) are today's best-studied drugs for erectile dysfunction anywhere in the world — sildenafil transformed sexual medicine back in 1998, and data from tens of thousands of patients have accumulated since. Yet plenty of oversimplifications still circulate about both drugs: from the belief that they work like an aphrodisiac, to underestimating one absolutely dangerous drug interaction. We check what the pivotal trials actually showed, how the two drugs differ, and what the real risks of using them are.
PZdr Piotr Zieliński14 min
September 4, 2026
GuidesPremature Ejaculation: Causes and Evidence-Based Treatment
Premature ejaculation is one of the most common — and least reported to doctors — sexual conditions in men; epidemiological estimates suggest it affects as many as one in three to four men at some point in life. Despite how common it is, plenty of misconceptions surround its treatment: from the belief that it's purely a matter of "willpower," to overlooking the fact that the best-studied drugs for this condition are, in practice, antidepressants working through a completely different mechanism than in depression. We check what the research on causes and treatment efficacy actually shows.
MWdr Marek Wójcik13 min
September 4, 2026
GuidesBone Density and Osteopenia: Why Prevention Starts Decades Before Menopause
Osteopenia — reduced but not yet clinically low bone mineral density — is often treated as a problem worth addressing only after menopause, or after a first worrying test result. Yet peak bone mass is usually reached before age thirty, and decisions made decades earlier — about training, diet, and screening — genuinely affect fracture risk at age 70 or 80. We check what the research on resistance training, calcium and vitamin D supplementation, and current screening guidelines actually shows.
KLdr Katarzyna Lewandowska13 min
September 4, 2026
GuidesHyaluronic Acid for Joint Pain: What the Evidence Shows for Injections and Oral Supplements
Hyaluronic acid is mostly associated today with facial cosmetics, but in medicine it's also been injected directly into joints for decades — to relieve pain in knee osteoarthritis — and, less commonly, taken as an oral supplement. These are two very different interventions with very different strength of evidence, often conflated in popular articles. We check what a large meta-analysis comparing injections to other treatments actually showed, why the American orthopedic association advises against routine injections, and what happens when hyaluronic acid is simply swallowed instead.
KLdr Katarzyna Lewandowska13 min
September 4, 2026
Guides5-HTP for Mood and Appetite: What the Research Shows — and Why It's Not a Supplement to Stack on Your Own
5-hydroxytryptophan (5-HTP) is a direct precursor of serotonin, sold as a supplement for mood, sleep, and appetite suppression. It's one of the few supplements whose mechanism of action — increasing serotonin production in the brain — is biochemically beyond dispute. That's exactly why it demands special caution: the same mechanism that may help with low mood or excessive appetite can, combined with antidepressants that raise serotonin levels, lead to serotonin syndrome — a rare but potentially life-threatening condition. We examine the evidence for both uses and explain why this interaction takes precedence over the question of effectiveness itself.
MWdr Marek Wójcik13 min
September 4, 2026
GuidesHow to Read Your Complete Blood Count — A Guide to the Basic Parameters
The complete blood count is one of the most commonly ordered lab tests — and one of the most commonly misunderstood. This step-by-step guide explains what abbreviations like RBC, WBC, PLT, MCV, and hemoglobin actually mean, how to read a result against its reference range, and when a value outside the normal range calls for an urgent doctor's visit versus when it's just ordinary, clinically meaningless fluctuation.
PZdr Piotr Zieliński11 min
September 3, 2026
GuidesPlant Protein for Vegans — A Ranking of the Best Sources
Giving up animal products doesn't have to mean compromising on protein intake, but it does require choosing sources deliberately and — in many cases — combining them. This guide ranks the best plant sources of protein by content, amino acid quality, and everyday practicality, backed by a real clinical trial showing that well-chosen plant protein can genuinely compete with whey.
AKdr Anna Kowalczyk12 min
September 3, 2026
GuidesThe Biohacker's Home Medicine Cabinet — 10 Supplements With the Strongest Evidence
Store shelves and online supplement rankings are overloaded with promises, but only a handful of substances have genuinely solid, repeatable scientific evidence behind them. This guide organizes 10 supplements with the strongest research support — from creatine to vitamin D — along with realistic doses, situations where they make sense, and situations where they're a wasted purchase.
AKdr Anna Kowalczyk12 min
September 3, 2026
GuidesIntermittent Fasting 16:8 or 5:2 — Which Eating Window Should You Choose
Intermittent fasting has spawned dozens of variants, but two protocols have dominated the public imagination: the daily, restricted 16:8 eating window and the cyclical, stronger calorie restriction of the 5:2 method. This guide compares both approaches based on real clinical trials, showing that the choice between them rarely comes down to which one is 'better' — and more often to which one you can actually stick with for longer than a few weeks.
PZdr Piotr Zieliński12 min
September 3, 2026
GuidesHow to Read Cosmetics Labels — Ingredients Worth a Closer Look
The ingredient list on a cosmetics package looks like a string of incomprehensible Latin names — yet it contains real, practical information about what, and how much of it, you're putting on your skin every day. This guide teaches you to read the INCI system step by step, points out ingredients worth a closer look, and shows, based on a real intervention study, that choosing products deliberately can measurably reduce exposure to certain substances within just a few days.
AKdr Anna Kowalczyk11 min
September 3, 2026
GuidesSleep Tracking Apps and Devices — What They Actually Measure, and What They Guess
A wrist watch, a finger ring, a mat under your mattress, or an app listening through your phone's microphone — each shows you a neat sleep-stage graph the next morning. The problem is that a large part of that graph isn't a measurement at all, it's algorithmic guesswork, and a study comparing eleven popular trackers against polysomnography shows just how much that guesswork can vary.
JWJulia Wiśniewska11 min
September 3, 2026
GuidesHow to Optimize Your Bedroom for Sleep Quality — a Step-by-Step Guide
The air temperature in your bedroom affects sleep quality more than most people realize — and it's just one of several environmental factors you can genuinely control without spending a fortune on a new mattress. Here's a practical guide to optimizing temperature, light, sound, and air quality in your bedroom.
JWJulia Wiśniewska11 min
September 3, 2026
GuidesElectrolytes During Exercise — When Plain Water Isn't Enough
Drinking large amounts of plain water during long, intense exercise sounds like an obviously safe hydration strategy — yet a study of Boston Marathon runners found that for some of them, it led to a dangerous dilution of blood sodium. Here's a practical guide to when and how to replace electrolytes during exercise.
MNMichał Nowak11 min
September 3, 2026
GuidesHow to Prepare for a Fasting Blood Test — What to Eat and Drink the Day Before
An analysis of results from 209,180 people found that fasting duration before a blood draw had a surprisingly small effect on total cholesterol — which challenges some common beliefs about how strictly you need to prepare for a routine blood test. Here's a practical guide to what actually matters the day before and on the day of the test.
PZdr Piotr Zieliński11 min
September 3, 2026
GuidesSupplements for Long-Distance Runners — What Actually Has Evidence Behind It
Store shelves and running influencers' profiles are groaning under supplements promising better long-distance performance, but the International Olympic Committee's official position points to only a handful of substances with solid evidence of effectiveness. Here's a guide to which ones actually matter for a long-distance runner, and which are marketing with no evidence behind them.
MNMichał Nowak12 min
September 3, 2026
GuidesHypothyroidism Symptoms That Are Easy to Mistake for Something Else
Fatigue, weight gain, hair loss, a worse mood — each of these symptoms on its own has dozens of other, more "obvious" explanations. That's exactly why hypothyroidism often gets diagnosed months, sometimes years, late. This guide shows step by step which symptoms are worth putting side by side and when it's actually worth getting a TSH test instead of blaming everything on stress or age.
PZdr Piotr Zieliński11 min
September 3, 2026
GuidesStrength Training for Women Over 40 — Where to Start
The decline in muscle mass, bone density, and metabolic rate after forty isn't a life sentence — it's largely reversible with strength training, even if you've never picked up a barbell before. This guide shows how to start safely, how much load you actually need, and what to avoid in the first few weeks.
MNMichał Nowak12 min
September 3, 2026
GuidesHow to Read Your Lipid Panel — Total Cholesterol Isn't the Whole Story
You get your lipid panel back, see "total cholesterol: normal," and close the topic? That might be premature. Total cholesterol is the sum of several fractions with very different clinical meaning, and a growing body of evidence suggests that the number of LDL particles (or apoB) says more about actual cardiovascular risk than the overall figure. This guide shows how to read a lipid panel line by line.
PZdr Piotr Zieliński11 min
September 3, 2026
GuidesThe First Week of a Ketogenic Diet — A Practical Guide
Headaches, fatigue, irritability, and "brain fog" in the first few days of a ketogenic diet have a name — keto flu — and a specific, well-documented cause. This guide shows, day by day, what to expect in the first week, how to actually ease the symptoms, and which mistakes to avoid so you don't quit on day three.
AKdr Anna Kowalczyk11 min
September 3, 2026
GuidesAn Evening Routine for Better Recovery — A Step-by-Step Guide
Recovery starts long before you close your eyes. What you do in the last two hours before bed — a screen in your hand, one last urgent email, a coffee "for the road" — has a direct effect on how deeply and how long you sleep, and therefore on how well you recover. This guide shows how to build an evening routine step by step, grounded in what sleep research actually shows.
JWJulia Wiśniewska10 min
September 3, 2026
GuidesImmune Supplements Before Cold and Flu Season — What Actually Works
Every autumn, pharmacy shelves fill up with a wave of "immune boosters." Some have real, evidence-backed grounding — the rest is marketing with no substance behind it. Here's a practical guide to what's actually worth focusing on before cold and flu season starts.
AKdr Anna Kowalczyk11 min
September 3, 2026
GuidesHow to Dose Caffeine to Match Your Body Weight and Tolerance
"Just have one coffee before your workout" ignores the fact that the same caffeine dose acts very differently in someone weighing 55 kg versus someone weighing 95 kg. Here's how to calculate a caffeine dose per kilogram of body weight, instead of guessing based on cup size.
MNMichał Nowak10 min
September 3, 2026
GuidesThe Wim Hof Breathing Method — What the Science Actually Says
Controlled hyperventilation, cold exposure, and mindset — the method popularized by Dutch extreme athlete Wim Hof made the jump from viral videos to one of the more widely cited studies on conscious control of the immune system. Here's what that study actually showed, and what's already marketing overreach.
JWJulia Wiśniewska12 min
September 3, 2026
GuidesHow to Prepare for Donating Blood — Diet and Hydration Before and After
Donating blood means losing roughly 450 ml in one sitting — including a meaningful amount of iron — yet most donors get no guidance beyond "eat something first" and "drink plenty of water." Here's a practical, step-by-step guide to what's actually worth doing before and after donating.
PZdr Piotr Zieliński11 min
September 3, 2026
GuidesCollagen — Hydrolysate or Peptides, Which Should You Choose? A Guide to the Forms
Collagen supplement shelves promise "hydrolysate," "peptides," "low molecular weight," and dozens of patented brand names — and most shoppers have no idea these terms largely describe the same process. Here's a guide to what actually separates these terms and what to look for when choosing.
AKdr Anna Kowalczyk11 min
September 3, 2026
GuidesQuercetin and Allergic Rhinitis: What Does the Clinical Trial Show?
Quercetin, a flavonoid found in onions, apples, and capers, has circulated online for years as a "natural antihistamine" for hay fever. A randomized, placebo-controlled Japanese study tested that claim in 66 people with pollinosis symptoms — and found a real, if modest, improvement. We look at exactly what was measured, what dose was used, and where the limits of this conclusion lie.
AKdr Anna Kowalczyk11 min
September 2, 2026
GuidesCholine and Nonalcoholic Fatty Liver Disease (NAFLD): What Does the Framingham Heart Study Show?
Choline is essential for transporting fat out of the liver, and its deficiency has been shown experimentally to cause fatty liver in humans within weeks. A new analysis of Framingham Heart Study data, covering more than 1,400 people followed for six years, shows that higher choline intake is associated with lower risk of developing nonalcoholic fatty liver disease (NAFLD) — with one important caveat regarding eggs as a choline source.
PZdr Piotr Zieliński12 min
September 2, 2026
GuidesN-Acetylcysteine (NAC) and COPD Exacerbations: What Does a Meta-Analysis of 13 Trials Show?
Exacerbations of chronic obstructive pulmonary disease (COPD) are the leading cause of hospitalization and worsened prognosis in patients with the disease. N-acetylcysteine (NAC), best known as a mucolytic, has a meta-analysis of 13 trials in over 4,000 patients behind it, showing a significant, dose-dependent reduction in exacerbation frequency. We look at what dose actually works, and for whom.
PZdr Piotr Zieliński12 min
September 2, 2026
GuidesVitamin D and Seasonal Affective Disorder (SAD): What Do the Studies Actually Show?
The theory linking low winter vitamin D levels to seasonal affective disorder (SAD) sounds intuitive and gets repeated readily in popular media. A randomized clinical trial designed specifically to test it, however, produced a result that rarely makes headlines: no significant difference between vitamin D and placebo. We take an honest look at what this hypothesis has going for it, and what still hasn't been proven.
JWJulia Wiśniewska11 min
September 2, 2026
GuidesProbiotics and Irritable Bowel Syndrome (IBS): Which Strains Have Real Evidence?
"Probiotics for IBS" is one of the most frequently repeated, but also most oversimplified, recommendations online. The largest meta-analysis to date — 82 trials and over 10,000 patients — paints a much more nuanced picture than supplement packaging suggests: a real benefit was confirmed only for select strains, and the certainty of that evidence was rated low in most cases.
AKdr Anna Kowalczyk12 min
September 2, 2026
GuidesMelatonin and Migraine in Children: Can a Supplement Replace Preventive Medication?
Migraine in children can seriously disrupt school, sleep, and daily life, and parents looking for a gentler alternative to prescription drugs increasingly come across melatonin as a preventive option. A carefully designed, randomized, placebo-controlled trial from the University of California, San Francisco, however, tells a much less clear-cut story than popular articles suggesting a ready-made solution.
JWJulia Wiśniewska11 min
September 2, 2026
GuidesCurcumin and Ulcerative Colitis: What a Meta-Analysis of Trials Shows
Ulcerative colitis (UC) is a chronic inflammatory disease in which patients increasingly look for extra support alongside standard mesalamine treatment. Curcumin, the active compound in turmeric, has a meta-analysis of six randomized trials behind it suggesting a real benefit as an add-on therapy — but as usual, the devil is in the details of dosing and formulation.
PZdr Piotr Zieliński12 min
September 2, 2026
GuidesVitamin E and Nonalcoholic Steatohepatitis: What the PIVENS Trial Found
Nonalcoholic steatohepatitis (NASH) is one of the few serious liver diseases that for decades lacked any approved pharmacological treatment. The large, multicenter PIVENS trial, published in the New England Journal of Medicine, showed that a high dose of vitamin E significantly improves liver histology in adults without diabetes — but with important caveats that are rarely discussed as loudly.
PZdr Piotr Zieliński12 min
September 2, 2026
GuidesGlucosamine and Temporomandibular Joint Pain: What a Trial Against Ibuprofen Found
Temporomandibular joint (TMJ) pain can accompany every bite, yawn, or conversation, and long-term use of nonsteroidal anti-inflammatory drugs like ibuprofen isn't a consequence-free solution. A small Iranian trial directly compared glucosamine sulfate with ibuprofen — with a surprisingly favorable result for the supplement, though broader systematic reviews call for tempering that enthusiasm.
MNMichał Nowak11 min
September 2, 2026
GuidesProbiotics and Acne Vulgaris: What a Randomized Clinical Trial Found
The link between the gut and the skin has stopped being just a lifestyle-article buzzword — a randomized clinical trial from 2024 tested a specific, well-described probiotic in patients with acne vulgaris and achieved a statistically significant improvement. It's still a single trial, but one worth discussing in detail, rather than lumping in with general "gut health" claims.
AKdr Anna Kowalczyk11 min
September 2, 2026
GuidesMagnesium and Restless Legs Syndrome in Pregnancy: What Does the Research Show?
Restless legs syndrome (RLS) affects a significant share of pregnant women, most often in the third trimester, and can effectively rob them of sleep at a time when rest matters most. A case-control study of 253 pregnant women found that blood magnesium and zinc levels were significantly lower in those with RLS than in healthy pregnant controls — but that's an observation, not proof that magnesium supplementation treats the symptoms.
AKdr Anna Kowalczyk11 min
September 2, 2026
GuidesOmega-3 and Atopic Dermatitis: Does Supplementation Actually Help?
Atopic dermatitis (AD) is a chronic inflammatory condition where parents and patients readily reach for supplements, hoping to ease itching and skin lesions without adding more medication. A 2024 randomized trial found significant improvement in AD severity in children taking a specific product — but that product combined omega-3, gamma-linolenic acid, and vitamin D, not fish oil alone, which matters a great deal for interpreting the result correctly.
AKdr Anna Kowalczyk12 min
September 2, 2026
GuidesVitamin B12 and Peripheral Neuropathy in Vegans and Vegetarians
Over 30% of adult vegetarians in the US may have a vitamin B12 deficiency — and that deficiency directly threatens the myelin sheaths of nerves. A small but carefully designed 2023 study was among the first to measure concrete, objective indicators of peripheral neuropathy — hand dexterity and balance — in young adults on a plant-based diet, and link them directly to B12 status.
PZdr Piotr Zieliński12 min
September 2, 2026
GuidesCinnamon and LDL Cholesterol: What Does the Meta-Analysis Actually Show?
Cinnamon is often marketed as a natural way to lower "bad" LDL cholesterol. A meta-analysis of 13 randomized trials involving 750 people, however, paints a more nuanced picture than the popular belief: cinnamon significantly lowers triglycerides and total cholesterol, but its effect on LDL specifically turned out to be statistically insignificant.
PZdr Piotr Zieliński11 min
September 2, 2026
GuidesProbiotics and Infantile Colic: When Do They Actually Help?
Infantile colic can turn the first months of parenthood into hours of unexplained evening crying. An individual patient data meta-analysis of 4 trials (345 infants) found that the strain Lactobacillus reuteri DSM 17938 significantly shortens crying time — but the effect was clear only in breastfed infants, not in those fed formula.
AKdr Anna Kowalczyk12 min
September 2, 2026
GuidesLemon Balm (Melissa officinalis) and Anxiety or Insomnia: What Does the Evidence Actually Show?
Lemon balm (Melissa officinalis) has been brewed into calming teas for centuries, but it's only in recent years that it has gotten a systematic review of clinical trials. A 2021 meta-analysis shows a statistically significant effect on anxiety and depression symptoms — with the caveat that the number of trials is small and the quality of evidence is moderate. Evidence for lemon balm's effect on sleep itself is far thinner — what we know comes mostly from single, small clinical trials.
JWJulia Wiśniewska11 min
September 2, 2026
GuidesCranberry and Recurrent Urinary Tract Infections: What Does the Updated Cochrane Review Show?
For years cranberry had a reputation as a home remedy for recurrent urinary tract infections, even though earlier large systematic reviews were skeptical about it. The latest, fifth update of the Cochrane review, from 2023 — now covering 50 studies and nearly 9,000 participants — changes that picture: in women with recurrent infections, cranberry products probably do meaningfully reduce the risk of another episode, though the effect is moderate and not visible in every patient group.
AKdr Anna Kowalczyk12 min
September 2, 2026
GuidesCoenzyme Q10 and Statin-Related Muscle Pain: What Does the Latest Meta-Analysis Show?
Muscle pain and weakness are among the most common reasons patients stop taking statins on their own — medications with well-documented cardiovascular benefit. Coenzyme Q10, whose production the body partially suppresses under statin therapy, has for years been recommended as a supplement to ease these complaints. A 2018 meta-analysis shows a real effect on muscle symptoms — but earlier analyses from the same decade reached the opposite conclusion, making this a good example of how much interpretation depends on which studies get selected.
PZdr Piotr Zieliński12 min
September 2, 2026
GuidesGinger and Migraine: Does It Help During an Acute Attack, or Only for Prevention?
Ginger is sometimes recommended as a natural way to ease a migraine attack, often alongside classic triptans or as an add-on to standard treatment. A 2021 meta-analysis pooling three randomized trials shows a real effect on pain during an acute migraine attack — but that's a completely different question from preventing migraines in the first place, where the evidence is much weaker, and one trial found no advantage of ginger over placebo.
JWJulia Wiśniewska10 min
September 2, 2026
GuidesFolic Acid and Postpartum Depression: What Does the Available Research Show?
Folic acid is mostly associated with preventing neural tube defects in the fetus, but a growing number of studies also look at its relationship with a mother's mood after childbirth. A 2022 meta-analysis suggests that continuous folic acid supplementation during pregnancy may be associated with a lower risk of perinatal depression — but this is still mostly observational data, not large randomized trials designed specifically for this purpose, which calls for caution in interpreting the conclusions.
AKdr Anna Kowalczyk11 min
September 2, 2026
GuidesZinc and Chronic Wound Healing: Does Supplementation Actually Help?
Zinc is often described as an almost universal wound-healing "accelerator" — from minor scrapes to venous leg ulcers that persist for months. The reality, as shown by the most rigorous systematic review available (Cochrane), is far more measured: in people with chronic leg ulcers, oral zinc supplementation, without first confirming an actual deficiency, did not statistically significantly speed up healing. That doesn't mean zinc is irrelevant to wound healing — it means its role shows up mainly where a real deficiency exists, not as a universal add-on for every patient.
PZdr Piotr Zieliński11 min
September 2, 2026
GuidesBerberine and Polycystic Ovary Syndrome (PCOS): What a Meta-Analysis of 10 Trials Shows
Berberine, a plant alkaloid best known for research on insulin resistance and type 2 diabetes, has in recent years gained popularity as a natural support for women with polycystic ovary syndrome (PCOS). A fresh meta-analysis of ten randomized trials gives a concrete answer to whether adding berberine to standard PCOS treatment actually improves fertility and hormonal profile — and shows the effect is real, but has clear limits.
AKdr Anna Kowalczyk12 min
September 2, 2026
GuidesCaffeine and Cognitive Function in Older Adults: What the Large Cohort Studies Actually Show
"Coffee protects against dementia" is one of the most repeated claims in popular guides about brain aging. The largest meta-analysis of cohort studies to date, covering over 750,000 participants, paints a far more ambiguous picture — and it's caffeine itself, apart from coffee and tea as whole beverages, that comes out looking weakest.
PZdr Piotr Zieliński12 min
September 2, 2026
GuidesPhosphatidylserine and Post-Exercise Cortisol: Does This Supplement Really Blunt Training Stress
Phosphatidylserine is often marketed to athletes and people training intensely as a way to "calm down" cortisol after a workout and speed up recovery. Behind this claim stands a specific double-blind, placebo-controlled crossover study — small, but methodologically solid. We take a close look at exactly what it showed, and what it didn't, before you decide on this fairly costly supplement.
MNMichał Nowak11 min
September 2, 2026
GuidesAshwagandha and Muscle Strength and Mass: What the Latest Meta-Analysis of 13 Trials Shows
Ashwagandha is today one of the most commonly supplemented adaptogens among people who train with weights, and supplement makers happily cite studies "proving" gains in strength and muscle mass. The latest, three-level meta-analysis pooling thirteen randomized trials gives a more measured answer: the overall effect is real, but specifically for muscle strength — what bodybuilders and strength trainees care about most — the evidence remains uncertain.
MNMichał Nowak12 min
September 2, 2026
GuidesProbiotics and Upper Respiratory Infections in Daycare and Preschool Children
The first year at daycare or preschool means, for many parents, an endless string of colds, runny noses and fevers — a child is healthy for two days, then sick again. Probiotics are among the most heavily marketed ways to "boost immunity" during this stretch, but a systematic review of the evidence paints a far more modest picture than the packaging suggests: the effect is real, but small, and depends on the specific strain rather than on probiotics in general.
AKdr Anna Kowalczyk11 min
September 2, 2026
GuidesVitamin D and Painful Periods — What an 11-Trial Meta-Analysis Shows
Dysmenorrhea — painful periods — affects a large share of women of reproductive age and is often dismissed as something you simply have to live with. A meta-analysis of 11 randomized trials shows that vitamin D supplementation significantly reduces menstrual pain intensity — but mainly for primary dysmenorrhea, not for pain secondary to other gynecological conditions.
AKdr Anna Kowalczyk11 min
September 2, 2026
GuidesL-Arginine and Preeclampsia Prevention — What a Systematic Review Says
Preeclampsia complicates 2 to 8% of pregnancies and remains one of the leading causes of maternal and neonatal complications. L-arginine, an amino acid that's a precursor of the vasodilator nitric oxide, has for years been studied as a potential, inexpensive preventive intervention in women at elevated risk — a systematic review of seven randomized trials shows a promising, though still uncertain, direction.
AKdr Anna Kowalczyk12 min
September 2, 2026
GuidesMelatonin and Sleep Quality in Children with ADHD — What a Randomized Trial Showed
Difficulty falling asleep affects a large share of children with ADHD, and the stimulant medications used to treat the disorder can make it worse. A randomized trial of 105 medication-free children shows that melatonin genuinely improves sleep measures — it shortens the time to fall asleep and lengthens sleep — but has no effect on ADHD symptoms themselves or on daytime behavior.
JWJulia Wiśniewska11 min
September 2, 2026
GuidesZinc and Chronic Urticaria — What Is Actually Known About This Link
Chronic urticaria — persistent hives and itching lasting weeks or months — is often linked online to zinc deficiency and "natural" treatment through supplementation. An honest look at the available scientific literature, however, shows something different: despite a mechanistically plausible hypothesis, dedicated clinical trials evaluating zinc specifically in chronic urticaria are essentially absent, and the one directly related study found no abnormality at all.
AKdr Anna Kowalczyk10 min
September 2, 2026
GuidesBenzoyl Peroxide Plus Clindamycin vs Azelaic Acid — What a Head-to-Head Trial Shows in Acne Vulgaris
Acne vulgaris is one of the most common skin conditions, and pharmacy shelves offer several proven topical treatments competing for attention. Azelaic acid is often marketed as a gentler, "natural" alternative, while benzoyl peroxide combined with clindamycin is positioned as a proven, stronger classic. One of the few direct head-to-head trials, published in the Journal of the European Academy of Dermatology and Venereology, pitted both regimens against each other in more than 200 patients with mild-to-moderate acne — and the result is not as clear-cut as the "gentler option" marketing narrative would suggest.
AKdr Anna Kowalczyk11 min
August 27, 2026
GuidesVitamin D and Psoriasis — Does Oral Supplementation Ease Symptoms?
Topical creams and ointments containing vitamin D analogues have long been standard, prescription treatment for psoriasis — that much is well established in dermatology. Far less clear is whether ordinary oral vitamin D supplementation — the same kind many people take in autumn and winter for immunity — has any effect on the course of the disease. A 2021 systematic review and meta-analysis of randomized trials tried to answer that question, and the result is more ambiguous than it might seem at first glance.
AKdr Anna Kowalczyk11 min
August 27, 2026
GuidesProbiotics and Eczema in Children — Do They Prevent Atopic Dermatitis?
Atopic dermatitis (AD, eczema) is one of the most common chronic skin diseases in infants and young children. For years, researchers have studied whether giving probiotics during pregnancy and early infancy can reduce the risk of it occurring in children at elevated risk. A large meta-analysis of 37 randomized trials involving more than 6,000 children shows a moderate but statistically significant protective effect — provided the probiotic reaches the child within the right, early time window. This is prevention in at-risk children, however, not treatment of already existing eczema — and that distinction is crucial.
AKdr Anna Kowalczyk11 min
August 27, 2026
GuidesIvermectin for Rosacea — How Does It Compare to Azelaic Acid?
Rosacea is a completely different disease from common acne, despite the confusingly similar name — and it needs different treatment. Ivermectin 1% cream is one of the newer treatment options, tested in two 40-week extension trials against azelaic acid 15%. We explain exactly what these trials showed, what they didn't show, and why this is primarily long-term safety data rather than a classic head-to-head efficacy contest.
AKdr Anna Kowalczyk11 min
August 27, 2026
GuidesZinc and Tinnitus — What Does the Cochrane Review Show?
Tinnitus can be exceptionally distressing, and treatment options remain limited — no wonder people affected by it look for solutions among supplements, including zinc. Cochrane, one of the most rigorous evidence-evaluating institutions in medicine, analyzed the available clinical trials on the topic. The result is an instructive lesson in the difference between a promising biological hypothesis and what well-designed studies in humans actually confirm.
PZdr Piotr Zieliński11 min
August 27, 2026
GuidesVitamin D and Asthma Exacerbations in Children — What Does the Meta-Analysis Show?
Asthma is the most common chronic childhood disease, and its exacerbations often lead to emergency room visits and hospitalizations. A 2024 meta-analysis of ten randomized trials examined whether vitamin D supplementation in children with asthma actually reduces the number of such exacerbations — and found a statistically significant, though moderate, effect. This is not, however, a reason to treat vitamin D as a substitute for asthma control medications, nor an argument for supplementing a child on your own without the treating doctor's knowledge.
PZdr Piotr Zieliński11 min
August 27, 2026
GuidesPulmonary Rehabilitation and COPD — What Does the Cochrane Review Show?
Chronic obstructive pulmonary disease (COPD) traps patients in a vicious cycle: breathlessness on exertion discourages movement, avoiding movement deepens deconditioning, and deconditioning worsens breathlessness at ever-lower levels of effort. Pulmonary rehabilitation — a structured exercise program combined with education, not just "breathing exercises" — is one of the few interventions that genuinely breaks this mechanism. The largest Cochrane review on the topic covered 65 randomized trials and nearly 3,800 participants — we look at exactly what it found.
MNMichał Nowak11 min
August 27, 2026
GuidesRiboflavin (Vitamin B2) and Migraine — What Does the Meta-Analysis Show?
Magnesium isn't the only supplement with meaningful scientific backing for migraine prevention. Riboflavin, vitamin B2, works through a completely different mechanism — not neurotransmission and vascular tone, but supporting the energy metabolism of nerve cells. A 2022 meta-analysis of nine studies and 673 participants shows that supplementing 400 mg of riboflavin daily for three months significantly reduced the number of migraine days, attack duration, frequency, and pain intensity. In this article we examine exactly what these results mean, how strong the evidence is, and why riboflavin is a separate, complementary option to magnesium rather than a substitute for it.
AKdr Anna Kowalczyk11 min
August 27, 2026
GuidesThe Ketogenic Diet and Drug-Resistant Epilepsy in Children — What Did the First Randomized Trial Show?
Before the ketogenic diet became a popular weight-loss approach, for nearly a hundred years it was — and still is — a serious, medically supervised therapy used in children with drug-resistant epilepsy, meaning epilepsy that can't be controlled despite correctly chosen antiepileptic drugs. In 2008, the first randomized controlled trial was published testing this intervention in a scientifically rigorous way — and it confirmed what neurologists had observed clinically for decades. This is an entirely different context than today's popular use of the keto diet for weight loss, which is easy to forget when seeing the same words applied to both.
PZdr Piotr Zieliński11 min
August 27, 2026
GuidesExercise and Parkinson's Disease — What Does the Meta-Analysis Show?
Parkinson's disease is a progressive neurodegenerative condition that cannot be reversed or "cured" by exercise alone. Yet a meta-analysis of 18 randomized trials with 901 patients shows that regular aerobic physical activity, carried out alongside pharmacological treatment, is associated with a moderate, statistically significant improvement in motor function. We explain exactly what was measured, how large this effect is, and why exercise remains an addition to therapy — not a replacement for it.
MNMichał Nowak11 min
August 27, 2026
GuidesVitamin D and Multiple Sclerosis — Does Supplementation Reduce Relapse Risk?
Low vitamin D levels and limited sun exposure have long been linked in observational studies to a higher risk and prevalence of multiple sclerosis (MS). This led researchers to ask whether vitamin D supplementation could actually reduce the number of disease relapses or slow the accumulation of disability in people already living with MS. A 2021 meta-analysis of nine randomized trials gave an answer that will surprise many — and shows just how large the gap can be between a strong observational association and a proven effect of intervention.
PZdr Piotr Zieliński11 min
August 27, 2026
GuidesExercise and Depression — What Does the Cochrane Review Show?
"Exercise helps with depression" is one of those recommendations you hear everywhere — from the doctor's office to social media. A Cochrane review covering 39 studies and more than two thousand participants does confirm a moderate effect of exercise on depression. But that same review contains a second, far less frequently cited number: when the analysis was restricted to only the most methodologically rigorous studies, the effect nearly disappeared. This is one of the best available lessons in how to read meta-analyses critically — and why the quality of studies, not just their number, determines the strength of a conclusion.
MNMichał Nowak11 min
August 27, 2026
GuidesL-theanine, Stress, and Anxiety — What Does a Clinical Trial Actually Show?
L-theanine, an amino acid best known as a mellowing companion to caffeine, is increasingly marketed on its own as a natural way to cope with stress and anxiety. A randomized, double-blind trial using magnetoencephalography (MEG) did find measurable changes in stress response and brain activity — but it's worth understanding exactly what was measured, in whom, and what these results do not prove about clinical anxiety disorder.
JWJulia Wiśniewska11 min
August 27, 2026
GuidesCognitive Behavioral Therapy for Insomnia (CBT-I) — What Does a Meta-Analysis Show?
When sleep falls apart, the simplest reflex is to reach for a sleeping pill. Yet for years, international sleep medicine guidelines have pointed to a completely different approach as the first-line treatment for chronic insomnia — cognitive behavioral therapy for insomnia (CBT-I). A large meta-analysis covering 87 randomized trials and over 6,000 participants shows why that recommendation isn't arbitrary.
JWJulia Wiśniewska11 min
August 27, 2026
GuidesProtein and Resistance Training vs. Sarcopenia — What Does the Research Review Show?
Sarcopenia — the progressive, age-related loss of muscle mass and strength — is often treated as an inevitable part of aging that little can be done about. A large umbrella review, covering 41 systematic reviews and roughly 4,475 primary studies, shows something else: a specific, quantifiable intervention (protein at 1.2 g/kg body weight per day or more combined with resistance training) alongside separate but related data on what actually reduces fall risk in older adults.
MNMichał Nowak11 min
August 27, 2026
GuidesCinnamon and Insulin Resistance — What Does the Meta-Analysis Show?
Cinnamon is one of the most frequently recommended "natural" interventions for insulin resistance — cheap, easy to find, and a kitchen staple for thousands of years. A current meta-analysis of 24 randomized trials does show a significant improvement in glycemic markers in patients with type 2 diabetes, but the evidence itself is more ambiguous than popular headlines suggest — the studies differ in cinnamon species, dose, and duration, and most cinnamon sold in stores (cassia) contains coumarin, a compound relevant to liver safety with long-term, high intake.
AKdr Anna Kowalczyk11 min
August 27, 2026
GuidesBeetroot Nitrates and Blood Pressure — What Does the Meta-Analysis Show?
Beetroot juice is often recommended as a natural way to lower blood pressure — thanks to its naturally high content of inorganic nitrates, which the body converts into nitric oxide, a potent vasodilator. A meta-analysis of 16 small crossover trials does show a statistically significant drop in systolic blood pressure, but the mechanism itself is more complex and dependent on individual factors than the headlines suggest — and most of the trials covered very short intervention periods.
PZdr Piotr Zieliński11 min
August 27, 2026
GuidesAlpha-Lipoic Acid and Diabetic Neuropathy — What Does the Meta-Analysis Show?
Diabetic neuropathy — pain, tingling, and numbness in the feet resulting from nerve damage caused by chronically elevated glucose — affects a substantial share of people with long-standing diabetes. Alpha-lipoic acid, a potent antioxidant, is one of the few supplements with a meta-analysis of several randomized trials showing a real improvement in symptoms. There is, however, an important detail that's easy to overlook: nearly all of this evidence concerns intravenous infusions in a clinical setting, not capsules bought at a pharmacy.
PZdr Piotr Zieliński11 min
August 27, 2026
GuidesVitamin C and Gum Disease — Does Supplementing or Rinsing With It Really Help?
The link between vitamin C and gum health is one of the oldest facts in medicine — scurvy, a disease caused by severe deficiency of this vitamin, has been associated with bleeding, swollen gums for centuries. But does that historical fact mean adding vitamin C to a mouthwash used alongside standard periodontal treatment gives an extra benefit to people who aren't deficient? A randomized trial from 2025 in 60 patients tested exactly that question — and the answer is more restrained than the packaging of vitamin C mouthwashes would suggest.
AKdr Anna Kowalczyk11 min
August 27, 2026
GuidesProbiotics and Women's Intimate Health — What Does the Meta-Analysis Show?
Bacterial vaginosis and vulvovaginal candidiasis are two completely different conditions that are often confused, and most women deal with one or the other at some point in their lives. A large 2024 meta-analysis covering 35 studies and more than 3,700 patients checked whether probiotics genuinely help treat and prevent recurrence of both conditions — and found clearly better outcomes, though the authors themselves note that more solid research is still needed.
AKdr Anna Kowalczyk11 min
August 27, 2026
GuidesExercise and Chronic Low Back Pain — What Does the Cochrane Review Show?
Chronic low back pain is one of the most common reasons for doctor visits and sick leave worldwide. For decades, the standard advice was rest — today, the largest available body of evidence, covering 249 clinical trials, shows the opposite: movement, not immobilization, is the approach backed by the strongest evidence. We check exactly what the 2021 Cochrane review found, how large the effect is, and for whom exercise isn't the first step.
MNMichał Nowak11 min
August 27, 2026
GuidesOmega-3 and Rheumatoid Arthritis — What Does the Meta-Analysis Show?
Rheumatoid arthritis (RA) is an autoimmune disease, completely different from the mechanical cartilage wear seen in osteoarthritis. A 2024 meta-analysis of 18 trials examined whether omega-3 supplementation actually helps RA patients — and revealed a picture more nuanced than a simple "yes, it's anti-inflammatory": a clear improvement in tender joint count, but no statistically significant improvement in standard inflammation markers.
PZdr Piotr Zieliński11 min
August 27, 2026
GuidesBiotin and Hair Loss — Does Supplementation Actually Help?
Biotin is one of the best-selling "hair" supplements — marketed as a universal fix for anyone, regardless of the cause of hair loss. The only systematic review on the topic shows something different: evidence for biotin's effectiveness applies almost exclusively to people with an actual, confirmed deficiency of this vitamin — and that deficiency is rare in developed countries on a normal diet. We check what's actually been shown, who supplementation might help, and who it likely won't help at all.
AKdr Anna Kowalczyk11 min
August 27, 2026
GuidesBiotin and Brittle Nails — What Did the Classic Study Show?
Brittle, splitting nails (onychoschizia) are a common cosmetic problem, and biotin has for decades been cited as one of the few supportive treatments with real, if modest, scientific backing. The classic 1990 Colombo et al. study, using electron microscopy, showed a specific improvement in nail thickness and structure in people taking biotin — though in a very small group of 32 people. That's an interesting contrast with the evidence for biotin in hair loss, which is much weaker — the strength of the evidence for biotin clearly depends on which outcome you're evaluating.
AKdr Anna Kowalczyk11 min
August 27, 2026
GuidesL-Citrulline and Erectile Dysfunction — What Did the Pilot Study Show?
L-citrulline, an over-the-counter amino acid best known from the world of training supplements, is also marketed as a natural aid for erections. Behind that claim is a specific study — small, pilot-stage, conducted in men with mild erectile dysfunction — that showed a surprisingly clear difference between placebo and supplementation. We look at exactly what was shown, what mechanism might explain it, and why the results of one small study should not replace a conversation with a doctor, especially for newly appearing erection problems.
PZdr Piotr Zieliński11 min
August 27, 2026
GuidesBlack Cohosh and Menopause Symptoms — What Does the Network Meta-Analysis Show?
Black cohosh (Actaea racemosa, also known as Cimicifuga racemosa) is one of the most popular herbal supplements for hot flashes and night sweats during menopause — marketed as a hormone-free alternative to hormone replacement therapy. A large network meta-analysis prepared for the UK's NICE menopause guideline did place it among the options more effective than placebo, but the picture is more nuanced than pharmacy packaging suggests.
AKdr Anna Kowalczyk11 min
August 27, 2026
GuidesMelatonin and Shift Work — What Does the Cochrane Review Show?
Shift work, unlike a one-off bout of jet lag, is a chronic, repeating conflict between the biological clock and the required sleep schedule. Melatonin is sometimes proposed as a way to improve sleep after a night shift, but a Cochrane review shows a more subdued picture than with jet lag: a real but modest effect, based on low-quality evidence.
JWJulia Wiśniewska11 min
August 27, 2026
GuidesUrsodeoxycholic Acid (UDCA) and Preventing Gallstones After Rapid Weight Loss
Rapid, large weight loss — typical after bariatric surgery or very restrictive low-calorie diets — significantly raises the risk of gallstone formation. A randomized controlled trial tested whether prophylactic ursodeoxycholic acid (UDCA) after bariatric surgery reduces that risk, and found a very large effect. This is not, however, advice about ordinary, gradual weight loss — we discuss exactly who these results apply to, and who they don't.
PZdr Piotr Zieliński11 min
August 27, 2026
GuidesSelenium and Mild Graves' Orbitopathy — What a Randomized Trial Showed
Graves' disease is hyperthyroidism — the opposite of the far more commonly discussed Hashimoto's. In some patients it's accompanied by Graves' orbitopathy, an inflammatory eye disease that can cause more suffering than the hyperthyroidism itself. A large, multicenter randomized trial published in the New England Journal of Medicine tested whether selenium helps in the mild form of this eye disease — and simultaneously showed that another tested drug, pentoxifylline, failed.
PZdr Piotr Zieliński11 min
August 27, 2026
GuidesB Vitamins (Folic Acid, B6, B12) and Cataracts — What a Large Trial in Women Showed
Folic acid, vitamin B6, and vitamin B12 are sometimes marketed as supporting eye health through antioxidant action and their effect on homocysteine levels. A large, randomized trial of nearly 4,000 women, run for over 7 years, found no protection against cataracts at all — and additionally showed a statistically significant increase in the risk of cataract surgery in the group taking these vitamins. This is a rare example of a supplement that not only failed to work, but may have actually caused harm.
AKdr Anna Kowalczyk11 min
August 27, 2026
GuidesCoffee and Liver Health — What Do Interventional Trials Actually Show?
Coffee has one of the best reputations of any commonly consumed beverage when it comes to liver health — decades of cohort studies link regular coffee drinking to a lower risk of cirrhosis and liver cancer. But when researchers pooled only randomized trials testing coffee's real effect on liver markers in patients with non-alcoholic fatty liver disease, the result turned out to be surprisingly modest. It's a good opportunity to look closely at the difference between observational and interventional evidence.
AKdr Anna Kowalczyk11 min
August 26, 2026
GuidesDiet and Lifestyle in Gastroesophageal Reflux Disease — What Actually Helps?
Gastroesophageal reflux disease (GERD), commonly known as heartburn, affects up to 30% of adults in Western countries. Around diet and lifestyle, a huge amount of advice has piled up — don't eat tomatoes, avoid spicy food, don't eat late — of very varying evidentiary strength. A systematic review published in Clinical Gastroenterology and Hepatology examined several specific interventions separately and showed that they don't all work equally well — some have solid, quantified effects, others rest on much weaker foundations.
AKdr Anna Kowalczyk11 min
August 26, 2026
GuidesMinoxidil and Female Pattern Hair Loss — What Does the Cochrane Review Show?
Female pattern hair loss affects millions, yet almost all popular knowledge about minoxidil — ads, forums, product packaging — is written with men in mind. A 2016 Cochrane review, covering more than a dozen trials conducted specifically in women, offers a rarely cited but concrete answer: minoxidil works measurably better than placebo, though the authors themselves rate the underlying evidence as moderate to low quality.
AKdr Anna Kowalczyk11 min
August 26, 2026
GuidesSaw Palmetto and Prostate Enlargement — What Does the Latest Cochrane Review Show?
Saw palmetto (Serenoa repens) is one of the best-selling herbal supplements in the world, marketed as natural support for men with benign prostatic enlargement and its urinary symptoms. In 2024, an updated Cochrane review — one of the most rigorous evidence sources in medicine — was published, covering 27 trials and more than 4,600 men. The result is clear and worth discussing honestly: high-certainty evidence shows that saw palmetto alone provides little or no real benefit for symptom relief.
PZdr Piotr Zieliński11 min
August 26, 2026
GuidesOmega-3 and Dry Eye Disease — What Did the DREAM Study Show?
Omega-3 supplements are one of the most commonly recommended "at-home" remedies for dry eye disease — by ophthalmologists, pharmacists, and countless online guides. The recommendation rests on a plausible anti-inflammatory mechanism and a handful of earlier, smaller studies. The large, rigorous DREAM trial, funded by the U.S. NIH and designed specifically to test this hypothesis, delivered a result that should change how we talk about omega-3 in the context of dry eye.
AKdr Anna Kowalczyk11 min
August 26, 2026
GuidesFlavonoids (Diosmin) and Hemorrhoids — What Does the Meta-Analysis Show?
Hemorrhoids are one of the most common complaints patients are least likely to mention out loud — embarrassment sends many people looking for answers quietly, where they run into contradictory advice. A 2020 systematic review and meta-analysis summed up what's actually known about oral preparations based on micronized purified flavonoid fraction (MPFF, built around diosmin) — with concrete numbers for bleeding, discharge, pain, and overall improvement, not vague claims like "helps with hemorrhoids."
AKdr Anna Kowalczyk11 min
August 26, 2026
GuidesFiber and Constipation — How Much, and What Kind, Actually Helps?
"Eat more fiber" is one of the most repeated, and least specific, pieces of advice for constipation. How much is "more"? Does the type of fiber even matter? And how long before you can expect it to work? An updated systematic review and meta-analysis of 16 randomized controlled trials with 1,251 participants gives answers far more concrete than a generic instruction to eat more vegetables.
AKdr Anna Kowalczyk11 min
August 26, 2026
GuidesHydration and Kidney Stones — How Much Does It Really Cut Recurrence Risk?
Kidney stones are one of the conditions with the highest recurrence risk in medicine — for someone who has already had one episode, another stone is more a matter of time than chance. A classic 5-year randomized trial from Parma showed that one simple, cheap, and practically safe intervention — just drinking more — meaningfully and measurably reduces that risk. It's a rare case in medicine where such strong evidence backs such simple advice.
PZdr Piotr Zieliński11 min
August 26, 2026
GuidesCherries and Gout — Do They Really Reduce Attack Risk?
Cherries as a home remedy for gout are one of the oldest pieces of advice on the internet — repeated so often that it's hard to tell folk tradition apart from real data. One of the few well-designed observational studies did find a strong, statistically solid link between eating cherries and a lower risk of a gout attack. The problem is it's still not a randomized trial — and the difference between these two types of evidence matters in practice, not just academically.
AKdr Anna Kowalczyk11 min
August 26, 2026
GuidesCalcium and Premenstrual Syndrome (PMS) — What Did the Classic Trial Show?
Premenstrual syndrome is often treated as something you simply have to live with — not as a condition that can actually be eased. One of the most frequently cited trials in this field showed that 1200 mg of calcium daily significantly reduced the severity of PMS symptoms after just two treatment cycles, with the effect growing with each subsequent cycle. It remains one of the best-designed studies in this area and a good starting point for talking about PMS as a condition worth diagnosing and treating, not just enduring.
AKdr Anna Kowalczyk11 min
August 26, 2026
GuidesLactase and Lactose Intolerance — Does Enzyme Supplementation Really Help?
Lactase tablets, taken just before a dairy meal, are one of the most popular ways of dealing with lactose intolerance — sold in nearly every pharmacy and drugstore. Unlike many digestive supplements whose mechanism of action can be murky, the logic here is simple: a missing enzyme is replaced with an external one. A randomized, placebo-controlled trial from India tested this directly, measuring not just perceived symptoms but also an objective physiological marker — the level of hydrogen in exhaled breath.
AKdr Anna Kowalczyk11 min
August 26, 2026
GuidesFlavonoids (Diosmin) and Chronic Venous Insufficiency — What Does the Meta-Analysis Show?
That feeling of heavy, swollen legs by the end of the day, nighttime calf cramps, sometimes visible varicose veins — chronic venous insufficiency affects a huge share of the adult population, especially people who stand or sit for a living. A large meta-analysis of 7 randomized trials with nearly 1,700 patients looked at how these symptoms respond to a micronized purified flavonoid fraction (MPFF, diosmin) — and found one of the lowest NNTs you'll ever see in supplement research.
PZdr Piotr Zieliński11 min
August 26, 2026
GuidesIron and Restless Legs Syndrome — When Does Supplementation Actually Help?
Restless legs syndrome (RLS) can quietly wreck sleep for years before anyone connects it to iron. A randomized trial shows that oral iron significantly relieves symptoms — but only in patients selected on the basis of a specific criterion: low-normal ferritin, confirmed by a blood test, not in everyone who has restless legs in the evening.
PZdr Piotr Zieliński11 min
August 26, 2026
GuidesVitamin K2 and Bone and Heart Health: What Does the Research Actually Confirm?
Vitamin K2 is often marketed as a supplement that simultaneously strengthens bones and "cleans" arteries of calcification — an attractive, two-part promise that sounds too good not to check against the source material. A meta-analysis of randomized trials does confirm the first part of that promise, but the best-designed, two-year clinical trial on the heart gives an answer that will surprise many — and shows why "the biomarker improved" isn't the same as "the hard clinical endpoint improved."
AKdr Anna Kowalczyk12 min
August 25, 2026
GuidesBeta-Alanine and Exercise Capacity: Who Does It Actually Work For?
Beta-alanine is one of the few pre-workout supplements whose effect can be felt almost tangibly — the characteristic skin tingling (paresthesia) after a dose leads many people to take effectiveness for granted. The largest available meta-analysis, covering over 1,400 participants and 65 different research protocols, shows something that requires real clarification: not every type of exercise responds to it the same way.
MNMichał Nowak12 min
August 25, 2026
GuidesOmega-3 Fatty Acids and Depression: Why Do Form and Dose Determine Effectiveness?
"Omega-3 for depression" is one of those recommendations heard so often that almost no one asks about the details — and in this case, the details decide everything. Two independent meta-analyses consistently show that the antidepressant effect isn't a property of "omega-3 fatty acids" as a whole, but of a specific fatty acid, EPA, within a specific, moderate dose range — and exceeding that range paradoxically weakens the effect instead of strengthening it.
JWJulia Wiśniewska12 min
August 25, 2026
GuidesAlcohol and Health: Is There a Safe Dose? What New Research Changed
For decades, "a glass of red wine a day protects the heart" was one of the most repeated, seemingly scientific health recommendations. Classic observational studies really did show that pattern — but a newer research method, one that eliminates a key methodological flaw underlying those studies, gives a fundamentally different answer. This is one of the most instructive examples of how a change in research method can overturn decades of seemingly settled knowledge.
AKdr Anna Kowalczyk13 min
August 25, 2026
GuidesRed Meat and Longevity: Why Isn't a Steak the Same as a Sausage?
"Red meat shortens your life" is a headline that flattens a much more nuanced topic. Two large, independent cohort studies clearly show that not every "red meat" carries the same risk — processed meat (deli meats, sausages, bacon) is linked to markedly higher death risk than unprocessed red meat, such as steak or roast, even though both are often lumped into one simplified category in popular dietary recommendations.
AKdr Anna Kowalczyk12 min
August 25, 2026
GuidesMelatonin and Jet Lag: What Do Clinical Trials Actually Say?
Melatonin is one of the few "jet lag" supplements to have earned its own Cochrane review — an organization regarded as the gold standard of rigor in evidence-based medicine. The conclusion from that review is surprisingly clear-cut by supplement-science standards, but comes with an honest caveat: it's an evidence base over two decades old, worth knowing precisely because newer, equally solid work rarely replaces it.
JWJulia Wiśniewska11 min
August 25, 2026
GuidesCitrulline Malate and Training Performance: Real Effect or Overhyped Supplement?
Citrulline malate is a staple ingredient in nearly every pre-workout on the market, marketed as a way to squeeze out noticeably more reps at the gym. The newest, and so far largest, meta-analysis on this topic from 2026 gives an answer more measured than the marketing suggests — the effect is real and statistically detectable, but certainty of evidence was rated low, and an earlier meta-analysis of the same question found a result that wasn't even statistically significant.
MNMichał Nowak11 min
August 25, 2026
GuidesCollagen and Skin Health: What Do Two Meta-Analyses Show?
Collagen powder or capsules are one of the fastest-growing segments of the beauty supplement market — and, rare for this category, one of the few where the popular promise ("firmer, better-hydrated skin") has earned solid confirmation in two independent, well-designed meta-analyses. This is a rare situation in supplement science, worth a closer look precisely because the evidence here is unusually consistent.
AKdr Anna Kowalczyk11 min
August 25, 2026
GuidesVitamin D3 and Testosterone: Where Did This Popular Theory Come From, and Does It Hold Up?
"Vitamin D raises testosterone" is one of the most repeated claims in the biohacking community, resting largely on one small study from over a decade ago. A newer, better-designed, and significantly larger randomized trial, conducted on healthy men, gave an answer that should clearly cool those expectations — and it's exactly this contrast that makes this topic worth tracing carefully.
PZdr Piotr Zieliński12 min
August 25, 2026
GuidesFasted Training and Fat Loss: A Real Mechanism, a Wrong Conclusion?
Fasted training has a reputation as a "hack" for faster fat loss — and, rare in the world of popular fitness advice, the underlying mechanism itself is scientifically true. The problem is that the study testing whether this mechanism translates into a real, long-term difference in body composition gave an answer that undermines the entire rationale for this strategy as a weight-loss tool.
MNMichał Nowak12 min
August 25, 2026
GuidesAspirin for Primary Prevention: Should Healthy People Take It Every Day?
"An aspirin a day for your heart" is one of the most enduring pieces of health advice of the 20th century — millions of healthy people in midlife and beyond, who had never had a heart attack or stroke, took it daily "just in case," often without a specific doctor's recommendation. Three large, independent randomized trials from recent years — including one with a genuinely surprising mortality finding — showed that in people who never had a cardiovascular event, daily aspirin provides essentially no measurable reduction in cardiovascular risk, while consistently increasing the risk of serious bleeding. The distinction between primary and secondary prevention is central here, and it's exactly the distinction that gets lost in casual conversation.
PZdr Piotr Zieliński13 min
August 25, 2026
GuidesVitamin D and Colds: What Do the Large Meta-Analyses Show?
"Vitamin D boosts immunity and protects against colds" is one of the most repeated claims in supplement conversations — and in this case, the popular claim is both true and misleading at the same time. Two large meta-analyses of randomized trials, including one built on individual participant data from 25 trials, show a real but modest protective effect against respiratory infections — provided vitamin D is taken daily or weekly in a moderate dose. The "one large dose per month or quarter" model popular in supplement marketing does not, in practice, deliver that effect. This article explains why how you dose matters more than the simple decision to supplement or not.
JWJulia Wiśniewska13 min
August 25, 2026
GuidesHigh-Dose Omega-3 and Atrial Fibrillation: An Unexpected Side Effect?
Omega-3 fatty acids have a well-established reputation as an unambiguously heart-healthy supplement. Two independent, large clinical trials evaluating high, prescription-strength omega-3 doses (4g/day) in cardiac patients show a consistent and concerning signal: this therapy meaningfully increases the risk of new-onset atrial fibrillation — an irregular heart rhythm — even in a trial where the same supplement produced a real, measurable cardiovascular benefit. This is not a warning about a typical over-the-counter fish oil supplement, but a specific signal tied to the high doses used to treat hypertriglyceridemia — a distinction that's easy to lose in simplified headlines.
PZdr Piotr Zieliński13 min
August 25, 2026
GuidesStatins and Type 2 Diabetes Risk: Do Cholesterol Drugs Raise Your Risk?
Statins are among the most widely prescribed drugs on earth, and their benefit in preventing heart attacks and strokes is one of the best-documented facts in all of cardiology. Less often discussed is another well-confirmed effect: statins genuinely increase the risk of newly diagnosed type 2 diabetes — not a fringe finding from a single study, but a result confirmed independently in the randomized JUPITER trial and in a meta-analysis of 13 trials covering more than 91,000 participants. The key, often-missed nuance is different from what the headline suggests: the increased risk falls almost entirely on people who already had diabetes risk factors, and the cardiovascular benefit of statins — even in that same group — is several times larger than the risk of causing one extra case of diabetes. This article explains why both facts are true at once, and why the authors of both studies, despite confirming the effect, unambiguously recommend continuing statin therapy.
PZdr Piotr Zieliński13 min
August 25, 2026
GuidesHigh-Dose Vitamin D and Falls in Older Adults: Does More Mean Worse?
"More vitamin D is better for bones" is one of the most widespread beliefs in osteoporosis and fall prevention for older adults. Two independent randomized trials — one Swiss, using monthly dosing, the other Australian, using a single annual dose — show the opposite: high, infrequently administered doses of vitamin D increased the number of falls, and in one case fractures too, despite raising blood vitamin D levels more effectively than standard doses. The problem turns out not to be the amount of vitamin D itself, but how it's delivered — a sharp spike in blood levels after a large, infrequent dose, rather than a stable level maintained through daily supplementation. This distinction matters directly for people over 70, for whom even a single fall can result in a hip fracture and permanent loss of independence.
AKdr Anna Kowalczyk13 min
August 25, 2026
GuidesAshwagandha and Male Fertility: What Did the Clinical Trial on Sperm Quality Show?
Ashwagandha is best known for lowering stress and cortisol, but a small Indian clinical trial tested something different: whether the same adaptogen could improve semen parameters in men with reduced sperm quality. The numbers from this pilot RCT are impressive — the question is how much can really be concluded from them.
PZdr Piotr Zieliński11 min
August 25, 2026
GuidesInositol and PCOS: What Does a Review of 13 Meta-Analyses Show?
Myo-inositol and D-chiro-inositol have featured for years in recommendations for women with PCOS as a way to improve insulin sensitivity, cycle regularity, and fertility. A new umbrella review pooling results from 13 earlier meta-analyses shows a consistent picture of benefit across hormones, insulin resistance, and ovulation — with one major caveat the authors themselves state outright: most of the underlying evidence is of low or very low quality, and the results "should not, on their own, guide clinical decisions."
PZdr Piotr Zieliński11 min
August 25, 2026
GuidesZinc and Male Fertility: What Did the Large FAZST Trial Show?
Zinc with folic acid is one of the most heavily marketed combinations "for fertility" in men. The largest and most rigorous trial on the subject — randomized, multicenter, in over 2,300 couples — tested whether this supplementation actually improves semen quality and the chances of a live birth. The result contradicts popular belief, and along the way reveals a signal that warrants caution.
PZdr Piotr Zieliński11 min
August 25, 2026
GuidesCurcumin and Joint Pain — Does It Work Like an Anti-Inflammatory Drug?
Curcumin is marketed as a "natural anti-inflammatory" for joint pain. One of the few studies to compare it head-to-head with a real drug — diclofenac — in patients with knee osteoarthritis paints a more interesting picture than the marketing slogans: similar pain relief, but clearly better tolerability and fewer side effects.
AKdr Anna Kowalczyk11 min
August 25, 2026
GuidesApple Cider Vinegar and Blood Sugar — Myth or Fact?
A spoonful of apple cider vinegar before a meal is one of the most popular wellness trends on social media — promising lower blood sugar, reduced appetite, and faster fat burning. The truth is more nuanced than the viral clips suggest: one randomized trial in people with type 2 diabetes did show a beneficial effect on glucose and lipids, but it's still a single, small study, not proof that vinegar replaces treatment.
AKdr Anna Kowalczyk11 min
August 25, 2026
GuidesMagnesium and Nocturnal Leg Cramps — Does Supplementation Actually Help?
Magnesium is the most commonly heard advice for nocturnal leg cramps — recommended by family doctors, pharmacists, and nearly every health guide. But the largest available systematic review (Cochrane, 11 trials, 735 participants) paints a far more complicated picture than a simple "yes, it helps": in people with idiopathic cramps, mostly older adults, the difference versus placebo was small and not statistically significant, while for pregnancy-related cramps the results remain conflicting and need further research. This isn't an article saying "magnesium doesn't work" — it's an attempt to show what's actually known, and what isn't.
AKdr Anna Kowalczyk11 min
August 25, 2026
GuidesProtein Before Sleep and Muscle Recovery — Does It Really Help Build Mass?
"Eat cottage cheese or take casein before bed so your muscles grow all night" — this is one of the more popular pieces of advice in strength-training circles, based on a real observation: protein consumed right before sleep really does raise the rate of overnight muscle protein synthesis. But the question is different: does this momentary, cellular-level effect translate into real, additional gains in strength and muscle mass after weeks of training? A 12-week randomized controlled trial tested this directly — and the result is more tempered than popular guides suggest.
MNMichał Nowak11 min
August 25, 2026
GuidesAshwagandha and Insomnia — What Did the Clinical Trial Show About Sleep Quality?
Ashwagandha is mostly associated with cortisol and stress, but one clinical trial tested something narrower and more clinical: does the same adaptogen help people with diagnosed insomnia — not just stressed, poorly-sleeping adults, but patients meeting the criteria for insomnia. A double-blind, randomized trial using actigraphy instead of questionnaires alone gives concrete numbers on shortened sleep onset and improved sleep efficiency.
JWJulia Wiśniewska11 min
August 25, 2026
GuidesVitamin D and Female Fertility — What Does the Largest Review of Studies Show?
Vitamin D is sometimes presented as almost a prerequisite for successful in vitro fertilization — clinics routinely test for it, and supplements are marketed as a way to improve the odds of pregnancy. The largest systematic review with meta-analysis to date examined this claim rigorously: the initial analysis did suggest a benefit, but after a sensitivity analysis the difference stopped being statistically significant — for clinical pregnancy rates, live births, and miscarriage alike. That doesn't mean vitamin D is unimportant for health — it just means it isn't a cure for infertility.
PZdr Piotr Zieliński11 min
August 25, 2026
GuidesGinger and Nausea in Pregnancy — What Does a Meta-Analysis of 12 Trials Show?
Nausea and vomiting of pregnancy (NVP) affect most women in the first trimester and can significantly lower quality of life. Ginger is one of the few home remedies actually backed by real, pooled evidence — a systematic review of 12 randomized trials in 1,278 pregnant women found a statistically significant improvement in nausea severity versus placebo, with no significantly increased risk of miscarriage or other adverse effects. It's not a miracle cure and won't replace treatment in severe cases, but it's rare to find a topic in this field with such a consistent, reassuring body of evidence.
AKdr Anna Kowalczyk11 min
August 25, 2026
GuidesTaurine and Longevity — What Do We Know, and What Don't We Know Yet?
In 2023, the journal Science published a headline-making study: declining taurine levels with age may drive aging, and supplementing it extended lifespan in mice and improved health in monkeys. Headlines quickly turned this into a "fountain of youth," but the study's own authors end their paper by saying that "clinical trials in humans seem warranted." We explain exactly what was shown in animals, what was merely correlated in humans, and why those two things are not the same.
AKdr Anna Kowalczyk11 min
August 25, 2026
GuidesLutein and Zeaxanthin for Macular Degeneration — What Does the Cochrane Review Actually Show?
Lutein and zeaxanthin are marketed as "vitamins for the eyes" almost everywhere vision comes up. The strongest available evidence — a Cochrane review covering 26 trials and nearly 12,000 participants — does show that a particular antioxidant combination slows the progression of age-related macular degeneration (AMD). The problem is that this effect applies to a specific, older supplement formula, a specific patient group, and isn't nearly as clearly attributable to lutein itself as most advertising suggests.
AKdr Anna Kowalczyk11 min
August 25, 2026
GuidesXylitol and Dental Caries — What Does the Cochrane Review Show?
Chewing gum, mints, and toothpaste containing xylitol are marketed as something more than a "sugar-free product" — as active protection against tooth decay. A systematic Cochrane review, covering 10 trials and almost 6,000 participants, tested this claim and found evidence that is much narrower, weaker, and more ambiguous than the marketing suggests — with one important methodological caveat rarely mentioned on the packaging.
AKdr Anna Kowalczyk11 min
August 25, 2026
GuidesCreatine and Kidney Health — Is Supplementation Safe?
“Creatine destroys your kidneys” is one of the most persistent supplement myths — repeated not only by online skeptics but sometimes by doctors who spot elevated creatinine in a patient's blood test. A fresh 2025 meta-analysis, covering 12 studies and 440 participants, lets us separate two things that are easily confused: a small, real rise in blood creatinine from actual damage to kidney function, as measured by GFR.
MNMichał Nowak11 min
August 25, 2026
GuidesOmega-3 and ADHD Symptoms in Children — What Does the Meta-Analysis Show?
Omega-3 fatty acids, specifically EPA, have for years been one of the most-studied supplements considered for ADHD in children — usually by families looking for something alongside stimulant medication, or hesitating before starting it. The most important meta-analysis on the topic, covering 10 studies and 699 children, did find a real, statistically significant effect. The catch is that the authors themselves call it “modest” and clearly smaller than the effect of medication — a distinction that matters before anyone treats fish oil as a replacement for established treatment.
PZdr Piotr Zieliński11 min
August 25, 2026
GuidesSleep Apnea and Weight Loss — Is Losing Weight Enough to Cure It?
Obesity is one of the strongest risk factors for obstructive sleep apnea, and weight loss — even the drastic kind achieved through bariatric surgery — can markedly improve its severity. But a meta-analysis of bariatric surgery studies reveals something rarely stated outright: despite the huge improvement, the average patient's sleep apnea usually doesn't disappear completely. It remains, just in a milder form — which has concrete, practical implications for the decision to continue treatment.
JWJulia Wiśniewska11 min
August 25, 2026
GuidesAshwagandha and Cortisol: Does This Adaptogen Really Lower Stress?
"Ashwagandha lowers cortisol" is one of the most repeated claims in the world of adaptogens — and, rarely for this kind of claim, one actually backed by solid numbers from meta-analyses. But the newest, largest meta-analysis to date, from 2025, shows something that changes how this effect should be understood: a drop in blood cortisol and a subjective feeling of reduced stress turn out to be two separate, not always linked, stories.
PZdr Piotr Zieliński12 min
August 24, 2026
GuidesCoffee and Longevity: What Do Large Cohort Studies Show?
Coffee has a reputation as either "something that raises your heart rate and dehydrates you" or one of the few everyday pleasures that actually extends life — depending on who you ask. Large, multi-year cohort studies covering hundreds of thousands of participants give a much clearer answer to this question than the popular, contradictory opinions suggest.
AKdr Anna Kowalczyk12 min
August 24, 2026
GuidesCreatine and Cognitive Function: Who Really Benefits for Memory and Focus?
For decades, creatine was associated purely with the gym — today it's increasingly marketed as a nootropic for anyone wanting sharper memory and focus. The newest meta-analyses, however, paint a far more selective picture than popular headlines suggest: the benefit for the brain is real, but clearly concentrated in specific groups, not universal for every healthy, young user.
PZdr Piotr Zieliński13 min
August 24, 2026
GuidesEggs and Blood Cholesterol: Does an Egg-Rich Diet Harm Your Heart?
For decades, eggs served as the poster child for a food to "avoid" if you cared about your heart — because of the high cholesterol content in the yolk. The newest, massive analysis combining three prospective US cohorts (215,618 people, followed for up to 32 years) and an updated meta-analysis spanning 1.72 million participants worldwide paints a far calmer picture: eating up to one egg a day shows no significant association with elevated cardiovascular risk. In Asian cohorts, researchers even observed a mild protective effect. This is one of those cases where the scale and quality of newer data shifts conclusions from decades past — not because the old studies were poorly done, but because newer analyses have the statistical power to catch nuances smaller samples couldn't see. In this article, we look at exactly what the numbers show, where certainty ends, and where nuance begins.
AKdr Anna Kowalczyk11 min
August 24, 2026
GuidesNon-Alcoholic Beer and Marathon Recovery: Does It Really Help Runners?
It sounds like a gym joke, yet it's one of the more intriguing findings in sports recovery science: a double-blind randomized controlled trial on 277 marathon runners found that drinking non-alcoholic beer for several weeks before and after a race cut the risk of upper respiratory tract infection more than threefold compared to placebo. This isn't locker-room folklore or brewery marketing — it's concrete data from the Munich Marathon, with measurements of interleukin-6, leukocyte counts, and actual illness tracking for two weeks after the race. In this article, we look at exactly what the study showed, what mechanism might explain it, and where scientific certainty ends and overinterpretation of a single, if solidly designed, experiment begins.
MNMichał Nowak11 min
August 24, 2026
GuidesCoffee and Iron Absorption: How Much Do You Really Lose Drinking Coffee With Meals?
If you drink coffee or tea alongside a meal, you're probably losing more iron from your food than you think — and this isn't an approximation from a pop-science article, it's a concrete figure from classic controlled human studies using radiolabeled iron. Coffee served with a standard meal reduced non-heme iron absorption by 35%, and tea by as much as 62% — nearly two-thirds of the iron the body could have absorbed simply passed through unused. Newer research adds a second dimension: this is a dose-dependent polyphenol effect, so strong black tea blocks far more than herbal tea, and adding milk doesn't actually rescue the situation, contrary to popular belief. For people with low ferritin levels or in a risk group for iron deficiency, this is a detail that can genuinely carry clinical weight.
JWJulia Wiśniewska12 min
August 24, 2026
GuidesMigraine and Magnesium: Does Supplementation Really Prevent Attacks?
Magnesium for migraine gets recommended almost reflexively, somewhere between grandma's advice and "just in case" supplementation — but this time there's more behind the recommendation than tradition. A fresh 2025 dose-response meta-analysis, covering 22 randomized trials, shows that magnesium supplementation reduced migraine attack frequency by an average of 2.51 episodes per month versus placebo, while also reducing pain severity and the number of migraine days per month. That result is comparable to, and in some respects better than, other well-known preventive interventions like CoQ10 or vitamin D. In this article, we look closely at what these numbers show, how they stack up against other supplements tested in the same study, and why this is a different topic from our article on magnesium and sleep quality — despite sharing the same mineral, the mechanism and clinical context are entirely separate.
PZdr Piotr Zieliński12 min
August 24, 2026
GuidesDaytime Napping: How Many Minutes to Avoid Sleep Inertia?
Intuition suggests a longer nap is a better nap — more recovery time should yield more benefit. A controlled sleep-lab study comparing 5, 10, 20, and 30-minute naps after restricted nocturnal sleep shows something surprisingly the opposite: a 10-minute nap produced nearly immediate, wide-ranging improvement in alertness and cognitive function, lasting up to nearly 2.5 hours, while a 30-minute nap triggered measurable sleep inertia — right after waking, participants performed worse, not better, before any benefit even appeared. This is one of those rare cases in sleep science where "less" genuinely means "better," not a trade-off. In this article, we look closely at what the Brooks and Lack crossover study showed, and how to translate that data into a practical napping strategy.
JWJulia Wiśniewska11 min
August 24, 2026
GuidesLemon Water on an Empty Stomach: Does It Really Speed Up Metabolism?
"Drink a glass of lemon water right after waking up to kickstart your metabolism" is one of the most repeated pieces of advice online, almost always without a source. The truth is more interesting than the myth itself: there's a solid study showing that plain drinking water genuinely, measurably raises metabolic rate — by as much as 24% within an hour of drinking it. The catch is that no human study has ever tested adding lemon to that water for its effect on metabolic rate or weight loss. This isn't a story about a "debunked myth" — it's about a myth nobody has formally tested, and that distinction matters. In this article we separate the two elements: what water actually does, and why we honestly can't say the same about lemon.
AKdr Anna Kowalczyk11 min
August 24, 2026
GuidesWalking After Meals: How Much Does It Really Lower the Post-Meal Blood Sugar Spike?
"Be active" is advice so general it barely tells you when exactly to move. A randomized clinical trial in people with type 2 diabetes found something far more specific: a short walk right after a meal lowers the post-meal glucose spike more effectively than a generic recommendation to "meet your daily activity target" without specifying timing. What's more, the effect wasn't the same across all meals — after dinner specifically, walking cut the glucose spike by roughly 22%, considerably more than after other meals of the day. This suggests that for blood sugar control, what matters isn't just how much you move over 24 hours, but precisely when you do it. In this article we break down these findings step by step and explain exactly which population they've been shown in.
MNMichał Nowak12 min
August 24, 2026
GuidesChewing Gum and Appetite: Does Chewing Gum Actually Help With Weight Loss?
"Chew gum instead of snacking" is advice almost everyone who's ever tried to control their appetite between meals has heard — but rarely does anyone check whether there's actually data behind it. It turns out there is, and from two independent experimental studies: chewing gum genuinely, measurably reduces later snack and calorie intake at the next meal. The catch is that the size of this effect is much more modest than the popular narrative of gum as a "weight-loss tool" would suggest — we're talking about a difference of a few dozen kilocalories, not hundreds. In this article we show exactly what was measured, how large the effect is in numbers, and why it's worth treating as an interesting but small piece of the puzzle rather than a standalone strategy.
AKdr Anna Kowalczyk10 min
August 24, 2026
GuidesPopcorn as a Snack: Fiber, Volume, and Satiety Versus Chips
Picture two snacks: a cup of potato chips worth 150 kcal and six cups of popcorn worth just 100 kcal — a huge difference in volume, but surely "a calorie is a calorie," right? Not necessarily. A controlled experimental study found that the much larger, less calorie-dense portion of popcorn produced a stronger feeling of fullness than the smaller portion of chips — and more strikingly, people who ate chips went on to eat more at their next meal than people who ate popcorn, even though the chips had delivered more calories in the snack itself. This study is one of the cleanest pieces of evidence that food volume, not just calorie count, has a real effect on how much we eat afterward. In this article we show exactly how the experiment was designed and what it means in practice.
AKdr Anna Kowalczyk11 min
August 24, 2026
GuidesArtificial Sweeteners and Insulin: Do They Raise Blood Sugar Despite Zero Calories?
"Zero calories, so zero effect on the body" is the assumption behind the popularity of artificial sweeteners among people watching their blood sugar — but two solid scientific studies paint a far more complicated, even contradictory, picture. A large network meta-analysis covering 36 studies found no effect of artificially sweetened beverages on glucose or insulin compared with water — but those studies mostly tested a single, one-off dose. Meanwhile, a 10-week clinical trial testing daily, chronic consumption of sucralose alone found a real, measurable rise in insulin levels and a drop in insulin sensitivity in healthy young adults. This contradiction is itself the most interesting takeaway of this article — because it suggests a single sip of a sweetened drink is probably nothing, but a daily, weeks-long habit might be something else entirely.
PZdr Piotr Zieliński13 min
August 24, 2026
GuidesMediterranean Diet and Longevity: How Much Does It Really Lower Death Risk?
"The Mediterranean diet extends life" is one of those statements repeated so often that almost no one asks for the actual numbers. By how much, exactly? For whom? And is this an effect visible after a few weeks, or only after decades of consistent adherence? In this article we break the topic down, drawing on the largest available meta-analysis (over 4 million participants) and a separate study focused specifically on older adults — two sources that together give a far fuller picture than the popular, oversimplified headlines.
AKdr Anna Kowalczyk14 min
August 23, 2026
GuidesCreatine and Hair Loss: Does the Supplement Really Raise DHT?
"Creatine causes baldness" is one of the most repeated warnings in gym culture — and it rests on exactly one study from 2009, which never measured hair loss at all. That study did show a real spike in DHT, the hormone responsible for pattern hair loss, up 56% after a week of creatine loading. The catch: nobody since has ever tested whether that DHT spike actually translates into real hair loss — and those are very different questions.
MNMichał Nowak11 min
August 23, 2026
GuidesCold Water After Strength Training: Does It Help or Block Muscle Growth?
An ice bath after a strength session is associated with recovery and professionalism — yet a 12-week study shows the opposite: people using cold water after every workout gained significantly less strength and muscle mass than people using standard active recovery. The culprit is suppression of the very molecular signals muscle relies on to grow after exercise.
MNMichał Nowak12 min
August 23, 2026
GuidesThe Post-Workout Anabolic Window: Myth or Real Time Limit?
"You have 30 minutes after training to eat protein, or you lose the gains" is one of the most deeply rooted beliefs in gym culture. A meta-analysis covering over 1,000 participants shows it's an oversimplification based on misreading short-term cellular signaling data. What matters is total daily protein intake, not a rigid minute-count after your last rep.
MNMichał Nowak11 min
August 23, 2026
GuidesHigh-Protein Diets and Kidneys: Do They Harm Healthy People?
"Too much protein wrecks your kidneys" is a warning almost everyone hears the moment they start eating more meat or protein powder. A systematic review shows higher protein intake raises glomerular filtration rate (GFR) — but that means the kidney is working harder within normal range, not that it's being damaged. There's an honest catch, though: almost no study ran longer than six months, so the truly long-term question remains open.
MNMichał Nowak12 min
August 23, 2026
GuidesAlcohol After Training: How Much Do You Really Lose From Your Muscle Gains?
One beer or a couple of drinks after a hard workout doesn't zero out the whole session's effects — but it isn't neutral either. A study published in PLOS ONE shows that alcohol consumed after strength training clearly lowers the rate of muscle protein synthesis, and pairing alcohol with protein doesn't fully protect against that drop. The good news: even after alcohol, protein synthesis remains elevated above resting levels.
MNMichał Nowak11 min
August 23, 2026
Guides8 Glasses of Water a Day: Where Does the Rule Come From, and Do You Need to Follow It?
The "8×8" rule — eight 8-ounce glasses of water a day — is one of the most repeated health tips in the world, and also one of the least documented. A systematic review of the scientific literature couldn't find a single study actually justifying that specific number for healthy adults in a temperate climate — and coffee and tea, contrary to popular belief, do count toward your daily fluid intake.
AKdr Anna Kowalczyk10 min
August 23, 2026
GuidesDaily Multivitamins: Do They Actually Help You Live Longer?
A daily multivitamin is one of the most purchased supplements in the world, driven by the belief that it's a simple "insurance policy" for a longer life. A massive cohort study covering nearly 400,000 US adults, followed for 27 years, shows the opposite of what you'd expect — people who regularly took a daily multivitamin had slightly higher, not lower, all-cause mortality than those who didn't.
AKdr Anna Kowalczyk12 min
August 23, 2026
GuidesCalories in Nuts: Why Is the Label Off by a Third?
The calorie count on a bag of almonds looks like a precise, scientific fact — yet a controlled feeding trial shows the body actually absorbs far less energy from them than the label suggests: 32% less. The reason is surprisingly physical, not chemical — a large chunk of the fat in almonds stays trapped inside intact plant cell walls and passes through the digestive tract undigested.
AKdr Anna Kowalczyk10 min
August 23, 2026
GuidesDark Chocolate and Your Heart: How Much Do You Actually Need to Eat?
The flagship COSMOS trial of over 21,000 people found daily cocoa flavanol supplementation didn't significantly cut total cardiovascular events — but it did cut cardiovascular deaths by 27%. A separate dose-response meta-analysis shows the vascular benefit peaks at around 700 mg of flavanols a day — far more than a typical bar of dark chocolate delivers, and one that doesn't keep improving with an even higher dose.
AKdr Anna Kowalczyk12 min
August 23, 2026
GuidesMagnesium Glycinate or Citrate for Sleep: What Does the Evidence Actually Say?
Search "magnesium for sleep" and you'll immediately land on a confident recommendation: glycinate, never citrate, because it "absorbs better" and "doesn't cause a laxative effect." The problem is that no study in healthy people with poor sleep has ever compared these two forms head-to-head — not for sleep quality, not for absorption. What looks like settled supplement wisdom is actually an evidence gap that marketing has filled with its own narrative.
JWJulia Wiśniewska11 min
August 23, 2026
GuidesDoes Melatonin Cause Weight Gain? What the Research Actually Shows
"Melatonin makes you gain weight" is one of those warnings that circulates on forums and Facebook groups without any specific source — yet it still effectively scares off people who might genuinely benefit from better sleep. A randomized clinical trial from 2021 tested this claim directly in overweight adults and found the opposite: in the second half of a 12-week intervention, the melatonin group kept losing body fat while the placebo group plateaued.
JWJulia Wiśniewska10 min
August 23, 2026
GuidesWeekend Sleep Debt: Does Catching Up Actually Pay It Off?
"I sleep 5-6 hours on weeknights, but I catch up on weekends" is one of the most commonly repeated strategies for coping with sleep loss — intuitive, convenient, and, as a well-controlled laboratory study published in Current Biology shows, probably wrong. Weekend catch-up sleep not only failed to protect participants from the metabolic consequences of sleep loss, but on some measures worsened the drop in insulin sensitivity more than getting no catch-up sleep at all.
JWJulia Wiśniewska12 min
August 23, 2026
GuidesCaffeine and Sleep: When Should You Actually Stop Drinking Coffee?
"No coffee after 3pm" sounds like a sensible rule — but a study published in the Journal of Clinical Sleep Medicine suggests even that cutoff may be too lenient. 400mg of caffeine (roughly the equivalent of 3-4 cups of coffee) disturbed sleep to a statistically significant degree regardless of whether it was given right at bedtime, 3 hours before, or a full 6 hours before bed — despite caffeine's roughly 5-hour half-life.
JWJulia Wiśniewska10 min
August 23, 2026
GuidesCollagen for Knee Pain: How Long Does It Take to Work?
Collagen supplement ads suggest quick relief from joint pain, but a well-designed, 6-month randomized clinical trial paints a very different picture: at 3 months, there was no significant difference at all between the collagen group and placebo. Only after a full 6 months did the share of people with meaningful pain improvement reach 51.6% in the collagen group versus 36.5% on placebo — a real difference, but one that requires patience the marketing usually leaves out.
JWJulia Wiśniewska11 min
August 23, 2026
GuidesMuscle Pain from Statins: Drug Effect or Nocebo?
Millions of patients stop taking statins because of muscle pain that, according to the first trial ever designed to settle the question, has nothing to do with the drug's pharmacology in 90% of cases. In the SAMSON experiment, participants reported nearly identical pain severity while taking the statin and while taking a placebo. That doesn't mean the pain is 'imaginary' — it means the pill itself, not its active ingredient, is usually not the source.
PZdr Piotr Zieliński11 min
August 23, 2026
GuidesAshwagandha and the Thyroid: Is It Safe with Hashimoto's?
"Ashwagandha is natural, so it can't harm the thyroid" — an assumption worth checking before reaching for this popular adaptogen with Hashimoto's or any other hypothyroidism. A randomized trial in people with subclinical hypothyroidism found that ashwagandha genuinely and significantly raised TSH, T3, and T4 — proof of real biological activity, but also a warning signal for anyone already on thyroid medication.
PZdr Piotr Zieliński11 min
August 23, 2026
GuidesSauna and Testosterone: Does It Raise or Lower It? The Research Says Both
The internet is split: some claim sauna "cooks" the testicles and lowers testosterone, others say it raises it. The truth is more complex and more interesting than either version: a single sauna session genuinely raises testosterone by about 15%, a hormonal response to heat stress similar to exercise. At the same time, regular, intense sauna use over months can damage sperm count and motility — with no effect on testosterone itself. These are two separate phenomena, governed by different mechanisms, easily confused with each other.
PZdr Piotr Zieliński12 min
August 23, 2026
GuidesIntermittent Fasting and Metabolism: Does Fasting Slow It Down?
"Don't go too long without eating, or your body will enter starvation mode and slow your metabolism" — one of the most commonly repeated warnings against intermittent fasting. A controlled 84-hour fasting study shows the opposite: short-term fasting didn't slow resting energy expenditure, it increased it, driven by more than a doubling of norepinephrine. 'Starvation mode' is a real phenomenon, but it applies to longer, more severe caloric restriction — not a fast lasting hours or even a couple of days.
PZdr Piotr Zieliński11 min
August 23, 2026
GuidesGarlic and LDL Cholesterol: Does It Really Lower It?
"Garlic lowers cholesterol" is one of the oldest folk health tips — and, rare for this category, partly confirmed by meta-analyses of clinical trials. But the devil is in the details: the effect is real (an LDL drop of about 9 mg/dL), yet it applies only to people with already elevated cholesterol, requires supplementation lasting more than 2 months, and has nothing to do with occasionally tossing a clove of garlic into dinner.
PZdr Piotr Zieliński10 min
August 23, 2026
GuidesVitamin C and the Common Cold: Does the Pauling Myth Hold Up?
Two-time Nobel laureate Linus Pauling argued in the 1970s that megadoses of vitamin C could prevent the common cold — a belief that still drives supplement sales worldwide today. The largest Cochrane review, covering over 11,000 participants, tells a far more nuanced story: for the average person, regular vitamin C supplementation barely moves the needle on catching a cold. But there's a clear exception — and the data behind it is some of the strongest in the entire review.
AKdr Anna Kowalczyk12 min
August 23, 2026
GuidesHormone Replacement Therapy in Menopause: Who Should Consider It, When, and What's the Real Risk?
The 2002 WHI study triggered a global panic around hormone replacement therapy, and prescriptions dropped by half almost overnight. Two decades of further analysis have painted a much more nuanced picture — one that depends above all on age and timing of initiation. We explain what the data actually show, who has a favorable risk-benefit balance today, and who should exercise particular caution.
PZdr Piotr Zieliński13 min
August 22, 2026
GuidesPCOS and Diet: What to Eat, What to Avoid, to Actually Support Your Hormones
"Eat a low-glycemic-index diet" is the one line PCOS hears most often — rarely explained in terms of what it actually means on your plate. We break down the evidence for low-GI versus low-carb, show what actually moves insulin and androgens, and point out where diet ends and myth begins.
AKdr Anna Kowalczyk12 min
August 22, 2026
GuidesEndometriosis and Fertility: What the Path to Pregnancy Actually Looks Like
"Endometriosis makes pregnancy impossible" is one of the most repeated, and least accurate, statements women hear after diagnosis. We check what the data on IVF with endometriosis actually show, which interventions genuinely improve the odds of pregnancy, and why hormonal treatment for pain doesn't always help when trying to conceive.
AKdr Anna Kowalczyk12 min
August 22, 2026
GuidesCold Showers and Immunity: Do You Really Get Sick Less?
"Cold exposure boosts your immune system" is one of the most repeated claims in biohacking — but the newest, largest meta-analysis on the topic shows something more complex: inflammation rises short-term, and immune markers don't budge. There is, though, one real, if surprising, long-term effect. We break down the evidence.
MNMichał Nowak11 min
August 22, 2026
GuidesHRV Training and Resonance Breathing: Does It Really Reduce Stress?
Your watch shows your HRV, but the measurement itself changes nothing. HRV training (biofeedback) is a specific technique — breathing at a resonance rate, usually around 6 breaths per minute — with real scientific support for reducing stress and anxiety. Here's how it works and how to start.
MNMichał Nowak10 min
August 22, 2026
GuidesRed Light Therapy and Muscle Recovery: When Does It Actually Work?
Photobiomodulation is mostly associated with skin, but a growing number of meta-analyses examine its effect on muscle strength and recovery. The result is more complex than a simple "works" or "doesn't work" — WHEN you apply the light and how trained the person is turn out to matter most. We break down the evidence.
MNMichał Nowak10 min
August 22, 2026
GuidesZinc and the Common Cold: Does It Really Shorten It?
"Zinc shortens colds" is one of the oldest claims in supplementation — and one of the few backed by meta-analyses with concrete numbers. But this story has an instructive plot twist: part of the key Cochrane evidence was withdrawn over data errors. We break down the topic, including what you shouldn't trust uncritically.
PZdr Piotr Zieliński11 min
August 22, 2026
GuidesSauna and Blood Pressure: What Do RCTs Show, Not Just Observation?
A Finnish cohort links regular sauna use to lower cardiovascular risk — but that's observational data, not an experiment. The newest meta-analysis of randomized trials checks what happens when you actually test heat's effect on blood pressure and other metabolic markers. The result is more measured than it might seem.
PZdr Piotr Zieliński10 min
August 22, 2026
GuidesZone 2 vs. HIIT: Which Improves VO2max More Effectively?
This is one of the most disputed topics in endurance biohacking. One meta-analysis suggests HIIT has an edge, another finds no difference between intervals and continuous training — but with a significant caveat about the quality of the studies analyzed. We check what the data really show before you pick one protocol over the other.
MNMichał Nowak11 min
August 22, 2026
GuidesProbiotics and Antibiotics: Do They Really Prevent Diarrhea?
This is one of the best-studied uses of probiotics — and one of the few cases where science points to a specific, best strain instead of a vague "probiotics help." We check how much the risk of antibiotic-associated diarrhea really drops, who benefits most, and which strain wins in head-to-head comparison.
PZdr Piotr Zieliński11 min
August 22, 2026
GuidesBerberine vs. Metformin: Does "Nature's Metformin" Really Measure Up?
"Nature's metformin" is one of the most repeated slogans in supplementation — and, surprisingly, one of the rare cases where a direct comparison with the drug actually exists. We check what that comparison really showed, how solid the 46-trial meta-analysis behind it is, and what popular headlines don't say about side effects.
PZdr Piotr Zieliński11 min
August 22, 2026
GuidesHow Many Sets Per Week Per Muscle Group? What the Meta-Analyses Show
"More is better" is an intuitive but incomplete summary of what's known about training volume. The classic Schoenfeld meta-analysis shows a continuous dose-response relationship, but a newer systematic review suggests a clear plateau around 12-20 sets per week. We break down these two seemingly contradictory conclusions.
MNMichał Nowak11 min
August 22, 2026
GuidesT3 and T4: Is Combining Thyroid Hormones Worth It Instead of Levothyroxine Alone?
Some hypothyroidism patients, despite normal TSH on levothyroxine alone, still report fatigue and brain fog — and look for an answer in combined T4+T3 therapy. We check what a meta-analysis of 16 randomized trials shows before you decide to ask your doctor for a treatment change.
PZdr Piotr Zieliński11 min
August 22, 2026
GuidesTRT and the Liver — Does Injectable Testosterone Actually Damage It?
"Testosterone destroys your liver" is one of the most repeated warnings about TRT — and one of the least accurate. We explain where the fear comes from, why the route of administration is absolutely decisive here, and what the research on injections, gel, and pills actually shows.
PZdr Piotr Zieliński13 min
August 20, 2026
GuidesBiohacking for Beginners — 10 Habits Worth Starting With
Before you buy your first gadget or supplement stack, start where the evidence is strongest: sleep, strength training, movement, food, and bloodwork. A practical guide to ten habits that give you the biggest return for the smallest investment.
AKdr Anna Kowalczyk13 min
August 20, 2026
GuidesNMN vs NAD+ vs Resveratrol — What Actually Extends Life?
Three of the biggest names in longevity, one shared hypothesis, and a very different level of evidence in humans for each. An honest comparison of mechanism, clinical trial quality, and monthly cost — with no marketing rounding up.
PZdr Piotr Zieliński14 min
August 20, 2026
GuidesVitamin D3 and Longevity — Does a Deficiency Shorten Your Life?
Low vitamin D levels correlate with higher mortality across dozens of observational studies, yet the massive randomized VITAL trial found no evidence that supplementation extends life in people without a deficiency. We break down this apparent contradiction piece by piece.
PZdr Piotr Zieliński13 min
August 20, 2026
GuidesSleep Biohacking — How Better Sleep Extends Your Life
Sleep tends to get treated as dead time, something to get through on the way to a productive morning. The epidemiological data says otherwise: both too little and too much sleep are linked to higher mortality risk, and sleep regularity turns out to matter more for survival than the raw number of hours. We gather what's actually known about sleep and longevity, and explain which sleep-biohacking habits actually have research behind them.
JWJulia Wiśniewska14 min
August 20, 2026
GuidesWhich Magnesium Should You Choose? Glycinate, Citrate or Lactate — Comparing the Forms
The supplement shelf can be overwhelming: glycinate, citrate, lactate, oxide, chelate... We compare the most popular forms of magnesium for absorption, price, and what each one is actually best suited for.
PZdr Piotr Zieliński10 min
August 18, 2026
GuidesWhich Collagen Should You Choose? Type I, II and III — What the Research Actually Says
Collagen is one of the most commonly bought supplements in Poland, yet few people know that 'collagen' isn't a single substance — it's a family of proteins with different uses. We explain the difference and help you pick the right type.
AKdr Anna Kowalczyk10 min
August 18, 2026
GuidesMelatonin, Magnesium, or L-Theanine? Comparing Sleep Supplements
The three most popular over-the-counter options for better sleep — and each works through a completely different mechanism. We look at which situation calls for which one, instead of reaching for all three at once.
JWJulia Wiśniewska10 min
August 18, 2026
GuidesIntermittent Fasting 16:8, 18:6, or OMAD? Which Eating Window to Choose
All three protocols restrict your eating window, but they differ enough that not every one suits everyone. We compare them on how hard they are to implement, the effects they produce, and who each variant makes the most sense for.
JWJulia Wiśniewska10 min
August 18, 2026
GuidesLow Testosterone: 12 Symptoms Men Often Don't Connect to Their Hormones
Fatigue, a flatter mood, trouble building fitness despite training — most men blame these on age, stress, or a lack of willpower. We look at which symptoms are actually worth linking to low testosterone, and why none of them, on its own, proves anything.
PZdr Piotr Zieliński12 min
August 15, 2026
GuidesHow to Raise Testosterone Naturally? What Actually Works vs. What's Marketing
The 'testosterone booster' market is worth billions, and most of it does nothing for a man with a normal hormone level. We check what real clinical trials say — from sleep and training to vitamin D, zinc, and ashwagandha — and separate genuine effect from marketing copy.
PZdr Piotr Zieliński13 min
August 15, 2026
GuidesTRT and Fertility: Can Testosterone Therapy Cause Infertility?
Testosterone replacement therapy can suppress sperm production even in men with a 'perfect' blood testosterone result — we explain the mechanism, the real scale of the problem, and the concrete options for men who want to have children.
PZdr Piotr Zieliński12 min
August 15, 2026
GuidesHow Long Does TRT Last? Is Testosterone Therapy for Life?
For most men with confirmed primary hypogonadism, TRT is a lifelong therapy — but in some with functional hypogonadism, it's possible to fix the underlying cause and return to natural production. We explain what this depends on, and what living on TRT for years actually means.
PZdr Piotr Zieliński11 min
August 15, 2026
GuidesTRT and Libido/Erections: Does Testosterone Really Improve Your Sex Life?
Testosterone raises libido more reliably than anything else in this therapy, but erections are a different story entirely — in many men over 40, normalizing the hormone alone won't fix the problem if something other than a testosterone deficiency is behind it.
PZdr Piotr Zieliński12 min
August 15, 2026
GuidesTRT Side Effects: What Should You Actually Worry About?
Internet forums warn of prostate cancer and heart attacks, while for most patients the real everyday issue is thicker blood and acne. We've sorted TRT's side effects by actual risk — not by what sounds the most terrifying.
PZdr Piotr Zieliński13 min
August 15, 2026
GuidesHow Long Until TRT Works? Testosterone Therapy Effects Week by Week
TRT doesn't work like a light switch — the real timeline of effects, grounded in pharmacokinetics and clinical trial data, stretches across months, not days. We break it down step by step so expectations don't drift away from reality.
PZdr Piotr Zieliński12 min
August 15, 2026
GuidesDoes TRT Cause Hair Loss, Acne, and Gynecomastia? Fact vs. Myth
Hair loss, acne, and 'man boobs' are the three most-Googled worries before starting TRT — but none of them is a guaranteed consequence of therapy. We check what physiology and the research actually say about mechanism, dose, and individual susceptibility.
PZdr Piotr Zieliński12 min
August 15, 2026
GuidesNormal Testosterone, But You Feel Awful — Could You Still Have Hypogonadism?
A testosterone result that comes back "in range" on a lab printout doesn't always mean everything is hormonally fine — but it doesn't automatically mean you have hypogonadism either. We explain four real explanations for this mismatch, ranked by strength of evidence.
PZdr Piotr Zieliński13 min
August 15, 2026
GuidesTRT Step by Step — What Does Starting Testosterone Therapy Actually Look Like?
From the first suspicion that "something's off" to a stable maintenance dose usually takes several months, not a few days — we walk through the entire, real process step by step, including the stages that most often disappoint at the start.
PZdr Piotr Zieliński13 min
August 15, 2026
GuidesTRT and Weight Loss — Does Testosterone Therapy Actually Help You Lose Weight?
Testosterone replacement therapy genuinely changes body composition in men with hypogonadism — less fat, more muscle — but it isn't a weight-loss drug, and the number on the scale after TRT often barely changes.
PZdr Piotr Zieliński11 min
August 15, 2026
GuidesTRT and Building Muscle Mass — What Can You Actually Expect From Therapy?
TRT genuinely increases muscle mass and strength in men with hypogonadism — but the scale of that effect is far more modest than bodybuilding forums suggest, and without strength training it remains a fraction of its potential.
PZdr Piotr Zieliński12 min
August 15, 2026
GuidesTRT and Sleep — Can Testosterone Improve Sleep Quality?
Poor sleep lowers testosterone — that's well documented. But does raising testosterone with replacement therapy improve sleep the other way around? The evidence is much weaker than for other TRT effects, and in some men therapy can actually worsen sleep apnea — so before asking "will it help me sleep," it's worth first asking whether untreated apnea might be the actual source of low testosterone.
PZdr Piotr Zieliński11 min
August 15, 2026
GuidesTestosterone and Fatigue — Can Low Testosterone Really Drain Your Energy?
Fatigue makes every list of low-testosterone symptoms, and TRT is sometimes marketed as a cure for low energy. The largest study ever to test this directly showed something different — and it's worth knowing before you go looking for the cause of your fatigue in your hormones.
PZdr Piotr Zieliński11 min
August 15, 2026
GuidesTestosterone, Depression, and Mood — Does Low Testosterone Affect Mental Health?
The link between low testosterone and low mood is real, but far more modest and less clear-cut than TRT clinic ads suggest — and testosterone therapy should never replace proven treatment for depression.
PZdr Piotr Zieliński12 min
August 15, 2026
GuidesLow Testosterone After 40 — Normal Aging or a Problem Worth Treating?
Testosterone in a forty-something man genuinely can be lower than it was at 25 — but "that's normal for your age" isn't an answer in itself. We explain how to tell a mild, expected decline apart from a situation that deserves proper testing and a real decision.
PZdr Piotr Zieliński12 min
August 15, 2026
GuidesLow Testosterone After 50 — Symptoms, Testing, and Treatment Options
Past fifty, the risk-benefit math on low testosterone looks different than it does at 40 — more coexisting conditions to factor in, more weight given to prostate and cardiac screening, but one topic usually stops being a problem: fertility.
PZdr Piotr Zieliński12 min
August 15, 2026
GuidesCan You Stop TRT? What Happens to Testosterone After Ending Therapy?
Testosterone doesn't drop to zero the moment you take your last dose — but in the weeks that follow, it almost always falls below pre-treatment levels before your own hormonal axis manages to wake back up. We explain what actually happens to the body after stopping TRT and how to do it safely.
PZdr Piotr Zieliński12 min
August 15, 2026
GuidesTRT, Alcohol, the Gym, and Diet — How Lifestyle Affects Testosterone Therapy
Alcohol doesn't "switch off" the effect of a testosterone injection the way it suppresses your own hormone production — but that doesn't mean it's irrelevant to therapy. We check what drinking, training, and diet actually change during TRT, and what's a myth repeated on forums.
PZdr Piotr Zieliński11 min
August 15, 2026
GuidesTestosterone and Hair Loss — Does TRT Speed Up Balding?
DHT, the androgen receptor, and hair follicle genetics: the full mechanism behind male pattern baldness in men on TRT, genetic testing, and an honest rundown of treatment options — from minoxidil to combining finasteride with testosterone therapy.
PZdr Piotr Zieliński13 min
August 15, 2026
GuidesTRT and Blood Pressure — Can Testosterone Therapy Raise It?
In some men, testosterone therapy measurably raises blood pressure — the effect is usually modest but real, and most strongly tied to a rise in hematocrit. That's not a reason to avoid TRT, but it is a parameter worth adding to routine monitoring alongside blood count, lipid panel, and PSA.
PZdr Piotr Zieliński11 min
August 15, 2026
GuidesTRT, Diabetes, and Insulin Resistance — Does Testosterone Affect Blood Sugar?
Low testosterone and insulin resistance go together far more often than chance would explain, and testosterone replacement therapy in men with hypogonadism and type 2 diabetes genuinely, though modestly, improves insulin sensitivity — but that's an addition to diabetes treatment, not a replacement for it.
PZdr Piotr Zieliński13 min
August 15, 2026
GuideshCG During TRT — When Is It Used, and Does It Help Preserve Fertility?
hCG gets added to testosterone therapy precisely so you don't lose fertility while on treatment — we explain what that looks like in practice: typical dosing, real-world effectiveness, and who it's actually a sensible option for, and who it isn't enough for.
PZdr Piotr Zieliński12 min
August 15, 2026
GuidesTRT and hCG — Can You Combine Testosterone Therapy with hCG?
Yes, combining TRT with hCG is an established, common clinical practice, not an experiment — but it comes with an extra injection, extra cost, and a real risk of pushing estradiol even higher, all worth knowing before you bring it up with your doctor.
PZdr Piotr Zieliński12 min
August 15, 2026
GuidesClomid or TRT — What to Choose for Low Testosterone?
Clomiphene and TRT raise testosterone through completely different routes — one stimulates the body to produce its own hormone, the other replaces it from outside. We explain why that difference matters critically for some men, especially around fertility.
PZdr Piotr Zieliński12 min
August 15, 2026
GuidesTRT or Natural Testosterone Boosting? A Practical Decision Test Before You Pick a Path
Before weighing the merits of TRT against the merits of lifestyle change, work out which of four situations you're actually in — because that, not preference or opinions from the internet, is what should decide your path.
PZdr Piotr Zieliński12 min
August 15, 2026
GuidesTRT and Gynecomastia — Why Does Breast Tissue Grow During Testosterone Therapy?
Gynecomastia on TRT is more than a single sentence in an article about side effects — it's a specific hormonal mechanism you can recognize yourself, track over time, and genuinely treat. A deep guide to aromatization, self-exams, and the real treatment options, from watchful waiting to surgery.
PZdr Piotr Zieliński13 min
August 15, 2026
GuidesTRT and Acne — Why Can Testosterone Cause Skin Problems?
Acne is the most common skin side effect of testosterone therapy — yet patients are rarely told exactly why it happens or what to actually do about it. We break down the sebaceous-gland mechanism step by step and lay out the full treatment ladder, from skincare to a dermatologist.
PZdr Piotr Zieliński13 min
August 15, 2026
GuidesTRT and High Estradiol — Symptoms, Causes, and What You Can Do About It
Suspect you have high estradiol on TRT? Before you reach for a forum post and someone else's anastrozole protocol, check which symptoms actually point to it and what order to act in — from bloodwork, through talking to your doctor, to a possible medication.
PZdr Piotr Zieliński12 min
August 15, 2026
GuidesThe Most Common TRT Mistakes — 15 Things That Can Undermine Your Therapy's Results
A wrap-up of our entire testosterone therapy series: fifteen common, real mistakes — from diagnostics to discontinuation — that can turn a well-designed TRT protocol into a source of disappointment or genuine health risk.
PZdr Piotr Zieliński17 min
August 15, 2026
GuidesHow to read supplement labels so you don't get fooled — a guide
What's stated on a supplement label doesn't always match what's actually inside the capsule. Here's a practical guide to what to look out for before you buy.
JWJulia Wiśniewska7 min
August 11, 2026
GuidesHow to build a workout routine when you're short on time — a minimalist's guide
Lack of time is the most commonly cited reason for giving up regular physical activity. We show a research-backed, minimalist way to stay fit on a very limited time budget.
MNMichał Nowak7 min
August 11, 2026
GuidesHow to Build a Morning Routine for Energy and Focus — A Step-by-Step Guide
The first hour after waking has a disproportionately large impact on your energy and focus for the rest of the day. Here's a practical, evidence-based guide to designing it.
JWJulia Wiśniewska7 min
August 4, 2026
Guides5 Biomarkers Worth Knowing Before 40 — Signals Before Symptoms Appear
A standard "once-a-year blood count" often misses early signs of metabolic and hormonal issues. Here are five markers worth asking your doctor about, before anything starts to hurt.
PZdr Piotr Zieliński7 min
August 1, 2026
GuidesKeto, DASH, or Mediterranean? Which Approach Has the Strongest Evidence for Weight Loss
We compare three popular eating patterns based on real scientific evidence — not social media popularity — to help you choose the approach that fits your goal.
MNMichał Nowak8 min
July 31, 2026
GuidesTRT or Lifestyle Change? What Actually Raises Testosterone Before You Consider Therapy
Before considering testosterone replacement therapy, it's worth checking how much sleep, training, and fat loss can realistically achieve — and when these interventions genuinely aren't enough.
PZdr Piotr Zieliński7 min
July 29, 2026