Blog
News, research and guides
348 articles from our editorial and science team.
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