Part Used: Dried rhizome & roots
Black Cohosh is a shrub-like plant native to the eastern deciduous forests of North America, ranging from southern Ontario to Georgia, north to Wisconsin and West to Arkansas. The strong odor of Black Cohosh flowers acts as an insect repellent. It is thus also known as bugbane. Black Cohosh is a stately perennial, 3-8 feet tall, topped by a long plume of white flowers (June-September). The leaves are large and pinnately compound; the leaflets are irregularly shaped with toothed edges. The dried root and rhizome are the constituents utilized medicinally.
Black Cohosh contains several important ingredients, including triterpene glycosides (e.g., acetin and cimicifugoside) and isoflavones (e.g., formononetin). Other constituents include aromatic acids, tannins, resins, fatty acids, starches, and sugars. Formononetin is the active element in the herb that binds to estrogen receptor sites, inducing an estrogen-like activity in the body. 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. Clinical studies from Germany have demonstrated that an alcohol extract of Black Cohosh decreases LH secretions in menopausal women. Black Cohosh is popular as an alternative to hormonal therapy in the treatment of menopausal (climacteric) symptoms such as hot flashes, mood disturbances, diaphoresis, palpitations, and vaginal dryness. Several studies have reported Black Cohosh to improve menopausal symptoms for up to six months. However, better-designed studies are needed before a firm recommendation can be made. Black Cohosh has an estrogen-like effect, and women who are pregnant or lactating should not use the herb. Large doses of this herb may cause abdominal pain, nausea, headaches, and dizziness. Women taking estrogen therapy should consult a physician before using Black Cohosh.
Holistic Online. http://www.holisticonline.com/Herbal-Med/_Herbs/h32.htm
Medline Plus. http://www.nlm.nih.gov/medlineplus/druginfo/natural/patient-blackcohosh.html