Common Names: black cohosh, black snakeroot, macrotys, bugbane, bugwort, rattleroot, rattleweed
Latin Name:
Actaea racemosa, Cimicifuga racemosa
Introduction
This fact sheet provides basic information about black cohosh—common names, what the science says, potential side effects and cautions, and resources for more information.
Black cohosh, a member of the buttercup family, is a plant native to North America. It was used in Native American medicine and was a home remedy in 19th-century America. Black cohosh has a history of use for rheumatism (arthritis and muscle pain) but has been used more recently as a folk or traditional remedy for 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, and to induce labor.
The underground stems and roots of black cohosh are commonly used fresh or dried to make strong teas (infusions), capsules, solid extracts used in pills, or liquid extracts (tinctures).
What the Science Says
Study results are mixed on whether black cohosh effectively relieves menopausal symptoms. An NCCIH-funded study found that black cohosh, whether used alone or with other botanicals, failed to relieve hot flashes and night sweats in postmenopausal women or those approaching menopause.
Most studies to date have been less than 6 months long, so the safety of long-term use is uncertain.
NCCIH is funding studies to further understand the potential effects of black cohosh on hot flashes and other menopausal symptoms.
There are not enough reliable data to determine whether black cohosh is effective for rheumatism or other uses.
Side Effects and Cautions
United States Pharmacopeia experts suggest women should discontinue use of black cohosh and consult a health care practitioner if they have a liver disorder or develop symptoms of liver trouble, such as abdominal pain, dark urine, or jaundice. There have been several case reports of hepatitis (inflammation of the liver), as well as liver failure, in women who were taking black cohosh. It is not known if black cohosh was responsible for these problems. Although these cases are very rare and the evidence is not definitive, scientists are concerned about the possible effects of black cohosh on the liver.
Some people taking black cohosh have experienced side effects such as stomach discomfort, headache, or rash. In general, clinical trials of black cohosh for menopausal symptoms have not found serious side effects.
Although concerns have been raised about possible interactions between black cohosh and various medications, a 2008 review of studies to date concluded that the risk of such interactions appears to be small.
It is not clear if black cohosh is safe for women who have had hormone-sensitive conditions such as breast cancer or for pregnant women or nursing mothers.
Black cohosh should not be confused with blue cohosh (Caulophyllum thalictroides), which has different properties, treatment uses, and side effects than black cohosh. Black cohosh is sometimes used with blue cohosh to stimulate labor, but this therapy has caused adverse effects in newborns, which appear to be due to blue cohosh.
Tell all your health care providers about any complementary health approaches you use. Give them a full picture of what you do to manage your health. This will help ensure coordinated and safe care.