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