Supplements

Collagen may modestly ease knee osteoarthritis pain. Evidence for skin, hair, gut health and weight loss is weaker. WEH verdict: uncertain.

Evidence check Ashwagandha has several possible short-term effects. None is as certain or as dramatic as many search results imply. WEH verdict: Mixed, low-certainty evidence The best-supported signals are modest improvements in some sleep measures and lower measured cortisol. Perceived stress is inconsistent, and a testosterone rise has not been shown to treat clinically low…

Evidence check Zinc lozenges are widely sold as a cold remedy. The best evidence suggests a possible modest reduction in how long a cold lasts, but the result is uncertain and depends heavily on which studies are included. The claim Oral zinc lozenges started soon after symptoms begin shorten the common cold. Plausible Low-certainty evidence…

WEH claim check Taurine is familiar from energy-drink cans and supplement labels, but it is also a compound your body already makes. Human trials suggest a few modest effects, while many popular claims run well ahead of the evidence. Human evidence included Cardiometabolic review 25randomized trials 1,024participants Exercise review 23randomized trials 308participants Separate meta-analyses; counts…

Supplement evidence review Glutathione is essential to normal biology, but that does not mean a supplement will detoxify the body, slow ageing or improve health. Some oral formulations raise measured glutathione levels. Meaningful health benefits remain unproven, and evidence for skin lightening is small and inconsistent. Last reviewed: 22 July 2026 The claim Glutathione supplements…

Evidence review A melatonin gummy looks like a sweet, but it delivers a biologically active hormone. The safety question has three separate parts: what melatonin does in a child’s body, whether the product contains the labelled dose, and whether its candy-like form increases accidental ingestion. Evidence checked through 17 July 2026 Claim being checkedMelatonin gummies…

WhatEvidence.Health Claim Check A careful look at the human evidence behind the mitochondrial health and healthy-aging supplement claim. WEH Verdict: Weak Urolithin A may help selected muscle fatigue or strength tests, but human evidence has not shown slower aging, longer life, disease prevention, or consistent everyday physical benefit. Claim checkedUrolithin A slows aging PopulationHealthy adults…

WhatEvidence.Health claim check Claim checked: taking L-theanine improves stress, anxiety, sleep, and focus. WEH Verdict: Promising, not proven L-theanine may modestly help short-term stress and perceived sleep quality, but it is not proven to treat anxiety disorders, insomnia, ADHD, or poor focus. Claim type Supplement benefit Best evidence Human RCTs and systematic reviews Population General…

Vitamin D is essential. But “essential” does not mean that extra vitamin D prevents every disease. WEH Verdict: Mixed Evidence Supported for deficiency. Not supported as a broad wellness cure-all. Claim type Supplement benefit Best evidence Guidelines, RCTs, meta-analyses Population General readers Last reviewed 10 June 2026 Bottom line Vitamin D is proven to help…