The popular herbal remedy black cohosh is no more effective than inactive pills at relieving menopausal symptoms such as hot flashes, a recent study shows.
Katherine Newton of the Group Health Co-operative in Seattle and her colleagues studied 351 women ages 45 to 55 years, of whom half were fully menopausal and half were experiencing irregular menstrual periods. All of the participants were experiencing two or more vasomotor symptoms per day, such as hot flashes and night sweats.
The researchers randomly assigned women to hormone replacement therapy, inactive placebo pills or one of three regimens of black cohosh. One group took 160 milligrams of black cohosh daily, another took 200 milligrams daily as part of a “multi-botanical” containing nine other herbal ingredients, and a third took the multi-botanical in conjunction with soy diet counselling, reflecting a common naturopathic approach. Soy contains substances that mimic the female hormone estrogen, and has also been touted as a possible treatment for menopausal symptoms.
Results at three, six and 12 months indicated black cohosh did not relieve vasomotor symptoms. “There was no difference from placebo,” Newton says.
The results may be disappointing for women and health-care providers who would like an alternative to hormone therapy for treating menopausal symptoms. “We went into this study with a very open mind because, despite the fact there have been other studies, we were not satisfied with the quality of those studies at that time, and felt that the answer was still out,” Newton says. “It is a disappointment because in general women do not want to be taking hormone therapy, and it would have been very nice to have something else to offer them. But our study would indicate black cohosh – at least as we delivered it – is not the answer.”
Newton says hormone therapy remains an option for severe menopausal symptoms. “For women with really disabling symptoms, they should be talking to their health provider, and they should be taking the lowest possible dose for the shortest period of time if they are going to use hormone therapy,” she said. “It’s still the most effective treatment for vasomotor symptoms in women.”