Ann Intern Med. 2003 Mar; 138(6): 468-71.

The relative safety of ephedra compared with other herbal products.

Bent S, Tiedt TN, Odden MC, Shlipak MG.

Osher Center for Integrative Medicine at the University of California, San Francisco, and San Francisco Veterans Affairs Medical Center, San Francisco, 111-A1, 4150 Clement Street, San Francisco, California 94121, USA. bent@itsa.ucsf.edu

BACKGROUND: Ephedra is widely used in dietary supplements that are marketed to promote weight loss or increase energy; however, the safety of this product has been questioned because of numerous case reports of adverse events. OBJECTIVE: To compare the risk for adverse events attributable to ephedra and other herbal products. DESIGN: Comparative case series. SETTING: American Association of Poison Control Centers Toxic Event Surveillance System Database Annual Report, 2001. MEASUREMENTS: The relative risk and 95% confidence interval for experiencing an adverse reaction after ephedra use compared with other herbs. This risk was defined as the ratio of adverse reactions to ephedra versus other products, divided by the ratio of their relative use in the United States. RESULTS: Products containing ephedra accounted for 64% of all adverse reactions to herbs in the United States, yet these products represented only 0.82% of herbal product sales. The relative risks for an adverse reaction in persons using ephedra compared with other herbs were extremely high, ranging from 100 (95% CI, 83 to 140) for kava to 720 (CI, 520 to 1100) for Ginkgo biloba. CONCLUSIONS: Ephedra use is associated with a greatly increased risk for adverse reactions compared with other herbs, and its use should be restricted.