Black cohosh (Cimicifuga racemosa) is a plant found in the buttercup family. It is also known as black snakeroot, bugbane, and squawroot. Black cohosh is a root that has estrogenic properties; it supplies estrogenic sterols which are the beginnings for steroid hormones like estrogen, progesterone and testerone. It was used to treat menopausal symptoms by Native Americans and colonists.
Black cohosh contains several ingredients, including triterpene glycosides (e.g., acetin and 27-deoxyactein) and isoflavones (e.g., formononetin). Other constituents include aromatic acids, tannins, resins, fatty acids, starches, and sugars. As a woman approaches menopause, the signals between the ovaries and pituitary gland diminish, slowing down estrogen production and increasing luteinizing hormone (LH) secretions. Hot flashes can result from these hormonal changes. Earlier animal studies and a human clinical trial6 suggested that black cohosh had some estrogen activity in the body and also decreased LH secretions. However, more recent animal studies and a clinical trial have found no estrogen activity for black cohosh extracts. The apparent healing properties of black cohosh root extend beyond its use for "women's problems." Thought to work as an anti-inflammatory and mild sedative, black cohosh may relieve muscle aches and pains. It has also been used to clear mucous membranes and lessen associated congestion and bothersome coughs.
Specifically, black cohosh may help to relieve hot flashes and other menopausal and perimenopausal symptoms. As estrogen levels decline in a woman's body during middle age, she may experience hot flashes, vaginal dryness, depression, and other unpleasant symptoms. Black cohosh may offset this decline in estrogen by providing powerful plant compounds called phytoestrogens that mimic the hormone's effects. These phytoestrogens bind to hormone receptors in the uterus, breast, and other parts of the body, possibly lessening hot flashes, vaginal dryness, headache, dizziness, depressive mood, and other hormone-related symptoms as a result. Black cohosh has antispasmodic properties that may lessen menstrual discomforts. In addition, by possibly increasing blood flow to the uterus, it may reduce the intensity of particularly painful cramps. By stabilizing hormone levels, the herb's phytoestrogens may even benefit women with premenstrual syndrome (PMS).