GradedHealth

Supplement safety

Evidence-graded topics and articles tagged Supplement safety.

Topics

  • Ashwagandha — Ashwagandha root extracts lower anxiety and stress scores and cortisol levels in meta-analyses of randomized trials, and small trials suggest better sleep.
  • Bacopa Monnieri — Bacopa is one of the most studied natural nootropics.
  • Berberine — Berberine meaningfully lowers fasting blood sugar and HbA1c in type 2 diabetes, with modest reductions in body weight.
  • Boswellia — Boswellia extract, made from the resin of the Indian frankincense tree, may ease knee osteoarthritis pain and stiffness, and some trials show better joint func…
  • CBD — Small trials suggest CBD can take the edge off anxiety, but a 54-trial review found no clear benefit.
  • Cranberry — Cranberry products - juice, capsules or tablets - help prevent repeat urinary tract infections: pooled trials found about a quarter to a third fewer infections…
  • Folate (folic acid) — Taken before and during early pregnancy, folic acid prevents neural tube birth defects such as spina bifida, cutting the risk by roughly 70% in pooled randomis…
  • Ginkgo Biloba — Ginkgo is among the most studied natural nootropics, with the clearest signals on perceptual and motor tasks.
  • Glucosamine and Chondroitin — Glucosamine and chondroitin may ease knee osteoarthritis pain a little, mainly in meta-analyses of smaller trials.
  • Green Tea — Small drops in weight and blood pressure in trials, with a small extra weight loss when combined with exercise.
  • Grey Hair — Premature greying is common, usually inherited, and linked to smoking and to some treatable deficiencies.
  • Lion's Mane — Small trials suggest lion's mane mushroom may slightly improve memory and thinking in older adults, especially those with mild memory problems or early Alzheim…
  • Lutein and Zeaxanthin — Lutein and zeaxanthin supplements raise the eye's protective pigment, and at 20 mg a day or more the rise is clear in pooled trials.
  • NAD+ Supplements — NR and NMN supplements raise blood NAD+ levels — by about 50% at 300 mg a day and more than double at 1,000 mg — and short-term use has been well tolerated.
  • Probiotics — Some probiotics may help prevent diarrhoea caused by antibiotics, with a smaller benefit against C.
  • Red Yeast Rice — Red yeast rice lowers LDL ('bad') cholesterol in trials, by roughly 20 to 40 mg/dL, because it naturally contains monacolin K — the same compound as the prescr…
  • Saffron — Saffron may modestly ease self-reported depression and anxiety symptoms, according to a 2026 meta-analysis of 34 trials.
  • Selenium — In trials, selenium improved eye signs and quality of life in people with mild Graves' eye disease, and in selenium-poor parts of China supplements cut the rat…
  • St John's Wort — St John's wort extracts ease mild to moderate depression: in pooled trials they worked better than placebo and about as well as standard antidepressants, with…
  • Testosterone Boosters — Some testosterone boosters modestly raise testosterone: in small trials, ashwagandha, fenugreek and tongkat ali lifted levels in men, and the hormone DHEA rais…
  • Turmeric — Several meta-analyses find curcumin eases knee osteoarthritis pain in short trials, though results vary widely.
  • Vitamin A — Vitamin A supplements prevent night blindness and other eye problems in people who are vitamin A deficient, and in low-income countries they cut child deaths b…
  • Vitamin C — Taken every day, vitamin C shortens colds by about 8% in adults and 14% in children and makes them less severe - a 2023 meta-analysis found severity fell 15%.
  • Zinc — Zinc lozenges taken at the start of a cold shorten the illness by roughly two to three days in randomised trials.