Do you know what's in those supplements?

A dozen ingredients commonly found in dietary supplements should be avoided, according to a new study by Consumer Reports, because they are linked to cancer, coma, kidney and liver damage, heart problems, and death.

The magazine singles out 12  ingredients it termed the ''dirty dozen." "The dozen we call out in this report are by no means the only dangerous ingredients," Nancy Metcalf, senior program editor at Consumer Reports, told WebMD. "They are the ones we chose to highlight."

Here's the list:

• Aconite, used for joint pain, wounds, gout, and inflammation, but linked with nausea, vomiting, heart rhythm disorders, respiratory system paralysis, and death.
• Bitter orange, used for weight loss, allergies, and nasal congestion, but linked with fainting, heart rhythm disorder, heart attack, stroke, and death.
• Chaparral, used for weight loss, colds, infections, inflammation, cancer, and detoxification, but linked to kidney and liver problems.
• Colloidal silver, used for fungal and other infections, Lyme disease, rosacea, psoriasis, food poisoning, chronic fatigue syndrome, and HIV/AIDS, but linked to bluish skin color, mucous membrane discoloration, neurological problems, and kidney damage.
• Coltsfoot, used for cough, sore throat, laryngitis, bronchitis, and asthma, but linked to cancer and liver damage.
• Comfrey, used for cough, heavy menstrual periods, chest pain, and cancer, but linked to liver damage and cancer.
• Country mallow, used for allergies, asthma, weight loss, bronchitis, and nasal congestion, but linked to heart attack and arrhythmia, stroke, and death.
• Germanium, used for pain, infections, glaucoma, liver problems, arthritis, osteoporosis, heart disease, HIV/AIDS, and cancer, but linked to kidney damage and death.
• Greater celandine, used for upset stomach, irritable bowel syndrome, liver disorders, detoxification, and cancer, but linked to liver damage.
• Kava, used for anxiety (and is possibly effective, according to Consumer Reports), but linked to liver damage.
• Lobelia, used for coughs, bronchitis, asthma, smoking cessation, but linked to toxicity, with overdose linked with fast heartbeat, very low blood pressure, coma, and possible death.
• Yohimbe, used as an aphrodisiac, for chest pain or diabetic complications, depression, and erectile dysfunction (and possibly effective, according to Consumer Reports), but linked to high blood pressure and rapid heart rate at usual doses and at high doses linked to severe low blood pressure, heart problems, and death.

Some things you can do, according the Metcalf:

• beware of products that have been linked with the most problems -- those for weight loss, sexual enhancement, and body building.
• buy products that have a "USP Verified" mark, which means the manufacturer has asked the U.S. Pharmacopeia, a nonprofit standards-setting authority, to verify the quality, purity, and potency of its raw ingredients or the finished product.
• check out alerts and advisories regarding dietary supplements on the web sites of the National Institutes of Health Office of Dietary Supplements and the FDA.