A review published in American Family Physician covers a broad range of herbal and dietary supplements for treating anxiety disorders.

I’ll focus on the best of the lot, kava (Piper methysticum). You can read the rest of the article here.

Evidence supporting kava to treat generalized anxiety disorder.

Cochrane Library

  • Kava was consistently better than placebo in producing small reductions in anxiety symptoms.
  • Side effects were “mild, transient, and infrequent.”
  • Kava taken for one to 24 weeks was safe and mildly effective.
  • Groups most susceptible to improvement were women and patients younger than 53 years.

Randomized clinical trials

  • Onset of effect is not rapid.
  • A 25-week study showed that therapeutic effects started in the 8th week.


  • Liver toxicity is rare and idiosyncratic.
  • It’s unclear if reports of liver toxicity were due to dosing, preexisting liver damage, or toxic combinations with other agents known to have effects on the liver.
  • The benefits of kava seem to outweigh its risks.

The bottom line”
The authors, who are from East Carolina University in Greenville, North Carolina conclude, “Encouraging data support the effectiveness of some of these products, particularly kava and, to a lesser degree, inositol. Although none of these supplements or products are free of adverse effects, the potential for benefit seems greater than the risk of harm.”

With respect to other supplements, “The existing data for St. John’s wort, valerian, and omega-3 fatty acids have little therapeutic value for anxiety disorders, and their use should be discouraged in favor of more effective treatments.”

As noted in a comment to an earlier post, it’s important to recognize the difference between anxiety and depression, and the presence of both before prescribing or taking treatment. It’s best to seek the advice of a professional first.

8/19/07 10:44 JR

Hi, I’m JR

John Russo, Jr., PharmD, is president of The MedCom Resource, Inc. Previously, he was senior vice president of medical communications at www.Vicus.com, a complementary and alternative medicine website.