Capsules containing kava. Touted as an anxiety-reducer and sleep aid, kava may cause liver damage and depression. (Brian Hagiwara/Getty Images)

Why you should avoid kava and 9 other risky dietary supplements

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One-third of Americans say they believe supplements have been tested by the Food and Drug Administration for safety, according to a 2022 nationally representative survey by Consumer Reports of 3,070 adults in the United States. But the FDA doesn’t approve or test the safety or effectiveness of any supplement before it enters the U.S. market.

After consulting with a panel of doctors and researchers, Consumer Reports says you should avoid these 10 risky supplements. In general, risk increases the larger the dosage and the longer the supplement is taken. Also beware of illegal or unapproved drug ingredients, such as tianeptine, methylsynephrine and phenibut.


Also called: creosote bush, greasewood, Larrea divaricata, Larrea tridentata, larreastat

Claimed benefits: weight loss; eases inflammation; treats colds, infections, rashes, cancers

Potential harms: kidney problems, liver damage


Also called: coughwort, Farfarae folium leaf, foalswort, Tussilago farfara

Claimed benefits: relieves cough, sore throat, laryngitis, bronchitis, asthma

Potential harms: liver damage, possible carcinogen


Also called: blackwort, bruisewort, slippery root, Symphytum officinale

Claimed benefits: relieves cough, heavy menstrual periods, stomach problems, chest pain; treats cancer

Potential harms: liver damage, cancer


Also called: Teucrium chamaedrys, Teucrium viscidum

Claimed benefits: weight loss; alleviates fever, arthritis, gout, stomach problems

Potential harms: liver damage, hepatitis

Greater celandine

Also called: celandine, Chelidonium majus

Claimed benefits: alleviates stomach ache

Potential harms: liver damage


Also called: ava pepper, kava kava, Piper methysticum

Claimed benefits: eases anxiety, helps sleep

Potential harms: liver damage, exacerbates Parkinson’s disease and depression, impairs driving


Also called: asthma weed, Lobelia inflata, vomit wort, wild tobacco

Claimed benefits: helps respiratory problems, smoking cessation

Potential harms: nausea, vomiting, diarrhea, tremors, rapid heartbeat, confusion, seizures, hypothermia, coma

Pennyroyal oil

Also called: Hedeoma pulegioides, Mentha pulegium

Claimed benefits: improves breathing problems, digestive disorders

Potential harms: liver and kidney failure, nerve damage, convulsions

Usnic acid

Also called: beard moss, tree moss, usnea

Claimed benefits: weight loss, pain relief

Potential harms: liver injury


Also called: Johimbi, Pausinystalia yohimbe, yohimbine, Corynanthe johimbi

Claimed benefits: treats low libido and erectile dysfunction, depression, obesity

Potential harms: raises blood pressure; causes rapid heart rate, headaches, seizures, liver and kidney problems, heart problems, panic attacks

Copyright 2022, Consumer Reports Inc.

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