Here are 10 risky supplements that CR, with the help of a panel of doctors and researchers, says you should steer clear of. 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.
Chaparral 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.
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Coltsfoot Also Called: coughwort, Farfarae folium leaf, foalswort, Tussilago farfara. Claimed Benefits: relieves cough, sore throat, laryngitis, bronchitis, asthma. Potential Harms: liver damage, possible carcinogen.
Comfrey 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.
Germander 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 Benefit: alleviates stomachache. Potential Harm: liver damage.
Kava 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.
Lobelia 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 Harm: liver injury.
Yohimbe 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.
Editor’s Note: This article also appeared in the January 2023 issue of Consumer Reports magazine.