NIH Trial Finds Black Cohosh Ineffective on Menopausal Symptoms

SEATTLEThe use of black cohosh extract alone or in combination with other botanicals was no more effective than a placebo treatment in reducing vasomotor symptoms of menopause, according to results of a one-year double blind trial, published in the Annals of Internal Medicine (145, 12:869-79, 2006). Funded by the National Institute on Aging (NIA) and the National Center for Complementary and Alternative Medicine (NCCAM), the Herbal Alternatives (HALT) for Menopause Study was conducted at the Group Health Center for Health Studies here and included 351 women, ages 45 to 55, with two or more vasomotor (hot flashes and/or night sweats) symptoms per day. Researchers compared the efficacy of black cohosh (160 mg/d); a multi-botanical (black cohosh 200 mg/d, plus alfalfa, boron, chaste tree, dong quai, false unicorn, licorice, oats, pomegranate and Siberian ginseng); the multibotanical-plus-diet counseling to increase soyfood consumption; conjugated equine estrogen (0.625 mg/d), with or without a progestin; or placebo.

At the end of one year, there was no significant difference seen between the number of daily hot flashes and/or night sweats in any of the herbal groups compared to the placebo group, with an average of 0.6 less vasomotor symptoms per day in the herbal groups. There was a significant difference4.06 fewer symptoms per dayin the hormone therapy group compared to the placebo group.

While researchers did point out the trial, did not simulate the whole-person approach used by naturopathic physicians, they concluded black cohosh alone or in combination therapy had little potential as an important therapy for relief of vasomotor symptoms.

In a release, Ruth Kirschenstein, M.D., acting director of NCCAM, said while the study may not have shown black cohoshs efficacy in relieving menopausal symptoms, it highlights the importance of studying herbs using well-designed research to find out what works and what does not. With this information, women and their physicians can have a meaningful discussion of complementary and alternative medicine approaches to menopause.