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5 Risky Herbal Supplements

Even though they're natural, some herbal supplements can be dangerous.
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St. John's Wort continued...

Besides, depression isn't something to treat without help. "It's not the common cold. If someone wants to use St. John's wort for depression, they still must be managed by a health care provider," McQueen tells WebMD.

Here's one major reason why: drug interactions. St. John's wort can make many other drugs less effective. There have been cases of unintended pregnancies in women taking St. John's wort and birth control pills and cases of organ rejection in those taking St John's wort with anti-rejection drugs after a transplant.

"If you are taking any prescription drug and are interested in trying a course of St. John's wort for mild to moderate depression, first discuss possible interactions with your doctor or pharmacist," says Weil, whose line of dietary supplements includes a product containing St. John's wort.

Kava

Kava (Piper methysticum) can reduce anxiety, and for some it has worked as well as prescription anti-anxiety drugs. But it may take up to eight weeks to work. In women experiencing anxiety in menopause, kava has worked in as little as one week, according to the National Institutes of Health.   

However, the National Institutes of Health and the FDA urge people not to take kava because of the risk of serious illness, liver damage, and death even when taken for only a short time at normal doses. Kava use has led to liver transplants and death in one to three months. "Heavy kava use has been linked to nerve damage and skin changes," Weil tells WebMD.

Kava can worsen depression and is not safe for women who are pregnant or breastfeeding. Because the herb has effects similar to those of alcohol, the two should not be combined.

A number of prescription drugs should not be combined with kava. The two drugs with the potential for greatest drug interactions are alprazolam (Xanax) and sedatives.

Weil only recommends kava for a maximum of three to four weeks in patients with healthy livers. "I do not recommend kava for people at risk for or who have liver disease, regularly drink alcohol, or take drugs with known adverse effects on the liver, including statins and acetaminophen."

Other experts have completely ruled kava out. "I prefer to use herbs that have a good risk-to-benefit ratio, and for kava that's no longer true," Fugh-Berman says.

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