• Settled groundDoes melatonin actually help jet lag? Less than the first trial foundOn flights across five or more time zones, melatonin taken near bedtime after landing eased jet lag. Two later trials found close to none, and counting them roughly halves the benefit.4 findingsMelatonin
• Is protein powder bad for your kidneys? Nobody has settled itIn 28 trials of healthy adults, kidney filtration changed no faster on more protein. A 13-year study found a signal in the top protein eaters. Neither shows harm or proves safety.1 findingDietary Protein
• Oil of oregano for a cold? Nobody has tested the capsules on oneOil of oregano capsules and drops sold for colds are untested in people with one, not disproven. A throat spray of a different oregano in a blend beat placebo at 20 minutes, not at day 3.2 findingsOil of Oregano
• Is melatonin bad for your heart? No randomised trial has tested a yearNo randomised trial has tested a year of nightly melatonin on the heart; sleep trials ran up to 29 weeks. In one gene study, insomnia itself went with 21% higher heart-failure odds.2 findingsMelatonin
• Does oil of oregano kill parasites? One test of 14, with no comparisonIn the only human test, gut parasites cleared in most of 14 adults after six weeks of oregano oil, but nobody went without it, so it cannot show the oil did it. No controlled trial has followed.2 findingsOil of Oregano
• Does Zicam shorten colds? Ultra RapidMelts' label gives no zinc amountIn one review, zinc lozenges shortened colds only above about 75 mg a day, a line drawn after the fact. The Zicam Ultra RapidMelts label names no zinc amount, so the box can't show if it gets near.2 findingsZinc
• Vitamin D and respiratory infections: the benefit shrank every rerunPooled three times by one team, vitamin D's protection against respiratory infections shrank until it lost statistical significance. A benefit in deficient people never returned but was barely tested.2 findingsVitamin D3 (Cholecalciferol)
• Does vitamin D give you energy? Nobody has tested everyday tirednessIn 120 tired, deficient young adults, fatigue fell further on vitamin D than on placebo over four weeks, though half on placebo improved too. Nobody has tested someone just tired with a normal level.1 findingVitamin D3 (Cholecalciferol)
• Myth checkDoes coffee raise blood pressure? The hour after, and the years afterWith high blood pressure, a 200 to 300 mg caffeine dose raised it for three hours or more in tests. Over years, coffee drinkers were no more likely than others to develop high blood pressure.2 findingsCaffeine
• ComparisonBack pain: Tylenol or an anti-inflammatory?For low back pain, paracetamol, the drug in Tylenol, came half a point ahead of placebo out of 100. Anti-inflammatories helped a sudden bad back a little; reviews split on how sure that is.2 findingsAcetaminophen (Paracetamol)NSAIDs (Non-Steroidal Anti-Inflammatory Drugs)
• Myth checkDoes Tylenol help a tension headache? Not in the first hourAcross 23 trials, 1,000 mg of paracetamol, the drug in Tylenol, was no different from placebo at one hour. By two hours, 22 people had to take it for one more to be pain-free.1 findingAcetaminophen (Paracetamol)
• Myth checkDoes coffee dehydrate you? A litre of it, tested against waterIn one small trial, a litre of coffee with 212 mg of caffeine left young men passing no more urine over four hours than a litre of water. Larger doses were not tested.1 findingCaffeine
• Do electrolyte drinks hydrate you better than water?In one test of 13 drinks, a sports drink held on to no more fluid than water. A rehydration solution and milk did, in men who were already fully hydrated.2 findingsElectrolyte Supplements and Sports DrinksSodium
• ComparisonTylenol or ibuprofen: which does more for the pain?For period pain, anti-inflammatories like ibuprofen beat paracetamol, the drug in Tylenol, though side effects rose. After surgery, one dose of the two together led a ranking of separate trials.2 findingsNSAIDs (Non-Steroidal Anti-Inflammatory Drugs)Acetaminophen (Paracetamol)Ibuprofen
• Myth checkComing off Wegovy or Ozempic: does the weight stay off?Mostly not. When stopping was randomised, weight came back while staying on took more off. A year after a trial ended, with coaching stopped too, most of the loss had returned.2 findingsSemaglutide
• Myth checkTylenol and your liver: almost half the failures were accidentsOf acetaminophen liver failures at 22 US units, 48% were accidents. Asked to show a day's use, 46% of patients handed two products containing it went past the daily limit.2 findingsAcetaminophen (Paracetamol)
• Does Benadryl cause dementia? The famous number is for a whole classNobody knows yet. The often-quoted 54% higher dementia rate was in the heaviest users of any strong anticholinergic drug, not antihistamines alone, and the big antihistamine studies disagree.2 findingsDiphenhydramine
• Myth checkTired all the time: is it low testosterone?The evidence doesn't point there. Tiredness and low mood did not group with a falling level, and a year of treatment in men over 65 improved sexual function but not fatigue.2 findingsTestosterone
• Myth checkAre two in five US adults really low on vitamin D?It depends who reads the test. 41.6 percent of US adults counted as deficient at one cutoff, and the same blood result is deficient or fine depending on the guideline.2 findingsVitamin D3 (Cholecalciferol)
• Myth checkBenadryl for sleep: you feel it working, the recordings don't show itPeople said they slept better; the electrodes showed no change. And in fifteen healthy men, its daytime drowsiness had worn off by day four.2 findingsDiphenhydramine
• Myth checkDoes taking vitamin C every day keep colds away?Across 24 comparisons, daily vitamin C left the chance of catching a cold essentially unchanged. Colds fell by about half only in five small, old trials of marathon runners, skiers and soldiers.2 findingsVitamin C
• Myth checkDoes the phenylephrine you swallow in DayQuil clear your nose?Swallowed, phenylephrine eased a blocked nose no more than a dummy pill in four modern trials, all in hay fever. No published modern trial has tested it alone in a cold.5 findingsPhenylephrine
• Myth checkVitamin C when you feel a cold coming on: does it do anything?Started once symptoms begin, vitamin C showed no consistent effect across seven comparisons. Colds ran slightly shorter only in people already taking it daily, and even that is disputed.2 findingsVitamin C
• Does zinc help with colds? The side effects are the surer resultZinc may take about two and a half days off a cold, but trials disagree so much that its non-serious side effects over a week of high-dose lozenges, a third more than placebo, are rated more certain.2 findingsZinc
• ComparisonAshwagandha or theanine for cortisol? It depends when you need itFor lower cortisol over the long run, the evidence points to ashwagandha taken daily. For a stressful task a few hours away, one trial points to a theanine drink taken beforehand.2 findingsAshwagandhaL-theanine
• Settled groundDoes ashwagandha actually move your stress hormone?Cortisol fell further on ashwagandha than on placebo across nine pooled trials, which recruited only adults already highly stressed. Nobody else, and nobody past sixteen weeks, has been followed.2 findingsAshwagandha
• A promising findingMagnesium beat placebo for depression. The evidence is 325 peopleMagnesium lowered depression scores well below placebo, across seven trials and 325 adults in total. An effect that large from so few people is usually what missing trials look like.1 findingMagnesium
• Myth checkA hundred experiments in, aspartame still did not move blood sugarTwelve randomised trials in one review, 100 controlled experiments in another, and neither could tell aspartame from a dummy drink on glucose or insulin. Finding no effect is not proof there is none.1 findingAspartame
• A promising findingBad sleep raises evening cortisol, and evening cortisol predicts sleepOne or two curtailed nights lifted evening cortisol by 30 to 45% and flattened the day's whole curve. Across 15 days, a higher bedtime reading came before a shorter, less efficient night.2 findingsCortisol
• Myth checkSplit melatonin's evidence by age and the adults drop outWith every age pooled, melatonin cut about 7 minutes off falling asleep. Split by age, that average belonged to children, teenagers and insomnia alongside another condition.1 findingMelatonin
• Myth checkStopping venlafaxine: was that withdrawal, or the depression back?Withdrawal tends to begin within days of stopping and fade over weeks, and in one trial ten symptoms appeared only in the people who had it. Of 21 guidelines, none said how to tell it from relapse.2 findingsVenlafaxine
• Myth checkIn a caffeine and theanine blend, the calm focus is the caffeineAcross 11 pooled trials, alertness tracked the caffeine more closely than the theanine. In one trial of 48 people, theanine flattened caffeine's blood-pressure rise but left jitters and mood alone.5 findingsCaffeineL-theanine
• ExplainerWhat actually happens to the collagen you drinkSwallowed collagen is broken down before it reaches skin, yet 113 trials find gains in elasticity, hydration and joint pain. The signal thought to explain that rests on animal and cell-dish work.4 findingsCollagen Peptides
• Myth checkThe creatine hair-loss worry came from a hormone, not from hairThe worry rests on an older study that loaded 25g a day for a week and measured a hormone. The one trial that looked at hair itself, 12 weeks at 5g, found no difference from placebo.1 findingCreatine
• Settled groundCreatine's gains are small, repeatable, and reach into old ageAcross 92 trials, creatine alongside lifting beat placebo on strength; the largest analysis in them put the bench edge at 1.43kg. A separate 12-trial pool found 1.14kg more lean mass under 50.5 findingsCreatine
• ComparisonOnly one of fish oil's two main fats moved depression scoresPooling 26 trials in 2,160 people who were also on antidepressants, omega-3 came out modestly ahead of placebo, almost entirely on the strength of EPA-built capsules rather than DHA.1 findingOmega-3 Fatty Acids (EPA/DHA)
• Myth checkNone of 2026's psilocybin news changed what psilocybin legally isAn April executive order, two programmes on the FDA's fastest review track and a bigger research quota landed in one year. Psilocybin is still Schedule I, with no approved product in the US.2 findingsPsilocybin
• A promising findingTheanine eased stress in an hour; cortisol took threeOne trial gave 26 adults a drink with 200mg of theanine and three other ingredients. Rated stress fell at one hour, cortisol at three, and the two never moved together.1 findingL-theanine
• Settled groundThe magnesium that stops a migraine fast is not the capsuleIn 948 people, magnesium given by drip brought an active migraine down within 15 to 45 minutes and still helped a day later. The capsule does a different job: fewer attacks, less severe.1 findingMagnesium
• ExplainerMagnesium is five different questions with five different answersThe same word covers a hospital drip that more than halved seizures in 10,141 pregnancies and a mood finding resting on 325 people. How far to trust it depends which claim you mean.5 findingsMagnesium
• Settled groundIn hospitals, magnesium is a life-saving drug, not a supplementBy drip, in 10,141 women with pre-eclampsia, magnesium sulphate cut eclamptic seizures by more than half and lowered the mother's risk of dying. Before a very early birth it cuts cerebral palsy risk.2 findingsMagnesium
• Settled groundMore melatonin did not mean more sleep, and 30 minutes was lateAcross 26 trials the sleep effect stopped climbing at around 4mg a day, and shifting it to about 3 hours before bed improved both how fast people fell asleep and how long they slept.1 findingMelatonin
• Myth checkGlutathione's marketing has its two forms the wrong way roundThe capsule sold as the weak option beat placebo, modestly and only on sun-exposed skin. The injections sold as premium never reached significance in their one controlled trial.2 findingsGlutathione
• Settled groundMagnesium's blood-pressure average is its least useful numberOver 8,610 people the upper reading fell 1.25 points. Among those taking 400mg a day for at least 12 weeks it fell 6.38, a number found by looking back through the data, not tested head on.2 findingsMagnesium
• Myth checkNobody has settled whether magnesium helps pregnancy leg crampsAcross four trials in 332 pregnant women, magnesium changed neither how often cramps came nor how fast they passed. Eight other trials disagreed too sharply to be pooled at all.2 findingsMagnesium
• A promising findingWhy stress can raise cortisol and inflammation at the same timeAcross 41 studies in mice, monkeys and people, long-running stress may leave immune cells less responsive to cortisol's anti-inflammatory signal, with inflammation rising even when cortisol is high.2 findingsCortisol
• A promising findingA single dose of cortisol was enough to dull recall within the hourForty healthy adults took 10mg of cortisol and an hour later recalled facts worse than adults on placebo. Older adults whose cortisol stayed high across five years had a smaller memory hub.2 findingsCortisol
• ExplainerCortisol is a curve, not a number, and stress bends it two waysCortisol peaks after waking and falls away; across the pooled research, the people whose fall is shallowest have worse health. Ordinary work pressure raised the morning surge, burnout went with less.2 findingsCortisol
• ComparisonDoes switching to diet cola save your teeth or your bones?Daily cola tracked with lower hip bone density in women, diet included. Teeth are where the switch shows: soaked seven days, Coca-Cola took more enamel than Coca-Cola Light, both less than juice.2 findingsPhosphoric Acid
• ComparisonDiet soda is not the low-risk half of the soda aisleIn long-running studies, each extra daily serving tracked with more heart disease for diet soda about as much as for sugary soda. Fourteen trials put the weight the swap takes off at 0.73kg.2 findingsAdded Sugar (Sucrose / HFCS)Aspartame+1
• Settled groundCortisol's most proven use is a drug given before an early birthOne course of corticosteroids, synthetic relatives of cortisol, given to women at risk of an early birth, cut newborn deaths and breathing failure. It is among obstetrics' best-established treatments.1 findingCortisol
• A promising findingHeart risk tracked the shape of the cortisol day, not the amountAmong 4,047 civil servants followed about six years, those whose cortisol fell least across the day died of heart disease 87% more often. Morning cortisol on its own showed no link at all.2 findingsCortisol
• Myth checkBerberine's metformin comparison ran once, in 36 peopleBerberine does lower long-term blood sugar, by about 0.4 percentage points across twenty randomised trials. The metformin match that made it famous came from one 36-person pilot with no placebo group.2 findingsBerberine
• Settled groundThe no-coffee headache is caffeine withdrawal, on a clockOne cup of coffee a day, 100mg of caffeine, is the smallest habit shown to produce withdrawal: ten validated symptoms, starting 12 to 24 hours after the last dose and running as long as nine days.1 findingCaffeine
• Myth checkIs venlafaxine really the hardest antidepressant to come off?Venlafaxine ranks third for withdrawal reports worldwide, and its fast clearance is the likely reason. But how often withdrawal actually happens to someone stopping it has never been pinned down.2 findingsVenlafaxine
• A promising findingThe smallest dose of venlafaxine may be the hardest one to dropImaging of related drugs shows effect rising steeply at low doses and flattening: the last cuts remove the most. Of 824 people on strips built on that idea, 72% stopped; none tapered without them.2 findingsVenlafaxine
• Myth checkTapering venlafaxine slowly wasn't the part that held off relapseAcross 76 trials, a slow taper with talking support halved relapse, matching staying on. A slow taper alone did not clearly beat stopping abruptly. The support seems to be what made the difference.1 findingVenlafaxine
• Myth checkBurnout comes with a smaller cortisol surge, not a bigger oneWork pressure came with a bigger morning cortisol surge, burnout with a smaller one; two short nights lifted evening cortisol up to 45% and nobody felt more stressed. Stress moves it, both ways.2 findingsCortisol