Black cohosh has a history of use for arthritis and muscle pain, but today, it is one of the more popular herbal remedies and nutritional supplements used primarily to treat hot flashes, night sweats, vaginal dryness and other symptoms that can occur during menopause. Black cohosh has also been used for menstrual irregularities and premenstrual syndrome, as well as to induce labor.

Black cohosh (known as both Actaea racemosa and Cimicifuga racemosa), a member of the buttercup family, is a perennial plant that is native to North America. Initial research on black cohosh suggests that it may improve some menopausal symptoms for up to six months. But while preliminary evidence is encouraging, the currently available data is not sufficient to support a recommendation on the use of the herb for menopausal symptoms.

How black cohosh works isn't understood. The safety of black cohosh in pregnant or breast-feeding women or children hasn't been established. Black cohosh is sometimes used by nurse-midwives to induce labor, but it should never be used by a pregnant woman without supervision by a qualified healthcare provider, because it could stimulate uterine contractions and result in miscarriage. Because black cohosh may act like the hormone estrogen in the body, it could also potentially interfere with hormone replacement therapy or oral contraceptives.