Black cohosh is often talked about as an herbal remedy for the symptoms of menopause. Researchers in Germany tested the herb in a clinical trial.

What the researchers wanted to know: Does Actaea racemosa or Cimicifuga racemosa, also known as black cohosh, alleviate the symptoms of menopause?

What they did: The researchers recruited 309 menopausal women, of whom 268 finished the study. All of them rated at least three of their menopause symptoms higher than 0.4 (on a scale of 1 to 10). Each woman was randomly assigned to get either black cohosh pills or placebo pills. Neither the women nor their doctors knew who had which treatment, and the pills looked the same. The study lasted 12 weeks; the women had physical exams and answered questions about their symptoms before the study and four and 12 weeks after they started taking the pills.

What they found: Women taking black cohosh were more likely to see improvement in some symptoms—hot flashes, for example—and overall scored their symptoms better at the end of the study than women taking the placebo. About 30 percent of women on each treatment, placebo and black cohosh, reported side effects, none of them serious.

What the study means to you: Black cohosh may relieve some menopause symptoms in some women. However, the use of this herb is still controversial. The National Institutes of Health says that there aren't enough data available yet to recommend using it and that data on long-term safety are especially lacking. Black cohosh is regulated as a food, not a drug, in the United States, which means that manufacturers don't have to prove it to be safe or effective before marketing it.

Caveats: This study only lasted 12 weeks; the supplement's effects and side effects could be different in the long run. Some of the researchers in this study work for Schaper & Brümmer, a German company that makes Remifemin, the black cohosh product tested in this study and in most other studies of the herb.

Find out more: Read a fact sheet about black cohosh, including what it's used for, a summary of clinical trials, and its potential harm, from the National Institutes of Health.

The American College of Obstetricians and Gynecologists told physicians in 2001 that in the short term, black cohosh might help women with vasomotor symptoms (symptoms having to do with dilation or constriction of the blood vessels, such as hot flashes). Read the whole bulletin at http://www.acog.org.

Read the article: Osmers, R., et al. "Efficacy and Safety of Isopropanolic Black Cohosh Extract For Climacteric Symptoms." Obstetrics and Gynecology. May 2005, Vol. 105, No. 5.