Black cohosh is one of the most promising natural remedies for relief of menopausal symptoms, particularly hot flashes. It contains triterpene glycosides, which researchers believe may interact with receptors in the brain to block some estrogenic activity. Since it has become so popular, many researchers are now investigating its long-term safety.

At the Department of Clinical and Experimental Endocrinology, University of Gottingen in Germany, researchers wanted to see how black cohosh compared to standard hormone replacement therapy for hot flashes, bone metabolism and endometrial growth. In this double-blind study, 62 postmenopausal women were given either black cohosh or a placebo for three months. Baseline tests were taken and compared to tests taken after the trial. These results showed that black cohosh was as effective as hormone replacement therapy (HRT) to reduce hot flashes and benefit bone health. And, unlike the hormone replacement therapy, black cohosh did not negatively affect endometrial growth.

Likewise, researchers at the Evanston Northwestern Medical School’s Healthcare Research Institute in Illinois found that black cohosh does not promote estrogenic activity or breast cancer cell growth. These researchers observed a group of women who were taking black cohosh and were also at high risk of developing breast cancer. The researchers conducted several tests to look for factors that would indicate growth of breast cancer cells. They found none.

Sources: Maturitas. 2003 Mar 14;44 Suppl 1:S67-77; Int J Oncol. 2003 Nov;23(5):1407-12