 Black Cohosh
Botanical name: Cimicifuga racemosa
Parts used and where grown: Black cohosh is a shrub-like plant native to the eastern deciduous forests of East-northeast in China. The dried root and rhizome are used medicinally. When harvested from the wild, the root is black in color. Cohosh, an Algonquin Indian word meaning "rough," refers to the plants gnarly root structure.
Black cohosh has been used in connection with the following conditions (refer to the individual health concern for complete information):
Historical or traditional use (may or may not be supported by scientific studies): Native Americans valued the herb and used it for many conditions, ranging from gynecological problems to rattlesnake bites. Some 19th century American physicians used black cohosh for fever, menstrual cramps, arthritis, and insomnia.
Active constituents : 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 trial suggested that black cohosh had some estrogen activity in the body and also decreased LH secretions. However, more recent animal studies and a clinical trial8 have found no estrogen activity for black cohosh extracts. Further clinical trials are needed to determine whether black cohosh has significant estrogenic actions in the body.
Small German clinical trials support the usefulness of black cohosh for women with hot flashes associated with menopause. A review of eight clinical trials found black cohosh to be both safe and effective for symptomatic relief of menopausal hot flashes. Other symptoms which improved included night sweats, insomnia, nervousness, and irritability. A clinical trial compared the effects of 40 mg versus 130 mg of black cohosh in menopausal women with complaints of hot flashes. While hot flashes were reduced equally at both amounts, there was no evidence of any estrogenic effect in any of the women. Although further trials are needed, this trial suggests that black cohosh is best reserved only for the symptomatic treatment of hot flashes associated with menopause and is not thought to be a substitute for hormone replacement therapy in menopausal and postmenopausal women.
A recent study suggests black cohosh may protect animals from osteoporosis. Human studies have not confirmed this action.
How much is usually taken ? Black cohosh can be taken in several forms, including crude, dried root or rhizome (300-2,000 mg per day), or as a solid, dry powdered extract (250 mg three times per day). Standardized extracts of the herb are available. The recommended amount is 20-40 mg twice per day. The best researched extract provides 1 mg of deoxyactein per mg of extract. Tinctures can be taken at 2-4 ml three times per day. Black cohosh can be taken for up to six months, and then it should be discontinued.
Are there any side effects or interactions ? Black cohosh should not be used by pregnant or breast-feeding women. Very large amounts (over several grams daily) of this herb may cause abdominal pain, nausea, headaches, and dizziness. Black cohosh is not a substitute for hormone replacement therapy during menopause.
At the time of writing, there were no well-known drug interactions with black cohosh. |
Contradictory, insufficient, or preliminary studies suggesting a health benefit or minimal health benefit. 