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