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© Steven Foster |
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 dried root and rhizome are used medicinally.1 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.2
Black cohosh has been used in connection with the following conditions (refer to the individual health concern for complete information):
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Dysmenorrhea (painful menstruation) |
Reliable and relatively consistent scientific data showing a substantial health benefit. Contradictory, insufficient, or preliminary
studies suggesting a health benefit or minimal health benefit. An herb is primarily supported by traditional use,
or the herb or supplement has little scientific support and/or minimal health benefit. |
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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.3
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 studies4 5 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 studies7 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.9 10 A review of eight clinical trials found black cohosh to be both safe and effective for symptomatic relief of menopausal hot flashes.11 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.12 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.13 Human studies have not confirmed this action.
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.14 The best researched extract provides 1 mg of deoxyactein per 20 mg of extract. Tinctures can be taken at 2–4 ml three times per day.15 Black cohosh can be taken for up to six months, and then it should be discontinued.16
Black cohosh should not be used by pregnant or breast-feeding women.17 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.
1. Leung AY, Foster S. Encyclopedia of Common Natural Ingredients Used in Food, Drugs, and Cosmetics, 2d ed. New York: John Wiley & Sons, 1996, 88–9.
2. Castleman M. The Healing Herbs. Emmaus, PA: Rodale Press, 1991, 75–8.
3. Foster S. Herbs for Your Health. Loveland, CO: Interweave Press, 1996, 12–3.
4. Jarry H, Harnischfeger G, Düker E. Studies on endocrine effects of the contents of Cimicifuga racemosa. 2. In vitro binding of compounds to estrogen receptors. Planta Medica 1985;51:316–9.
5. Jarry H, Harnischfeger G. Studies on endocrine effects of the contents of Cimicifuga racemosa. 1. Influence on the serum concentration of pituitary hormones in ovariectomized rats. Planta Medica 1985;51:46–9.
6. Düker EM, Kopanski L, Jarry H, Wuttke W. Effects of extracts from Cimicifuga racemosa on gonadotropin release in menopausal women and ovariectomized rats. Planta Medica 1991;57:420–4.
7. Einer-Jensen N, Zhao J, Andersen KP, Kristoffersen K. Cimicifuga and Melbrosia lack estrogenic effects in mice and rats. Maturitas 1996;25:149–53.
8. Liske E, Wüstenberg P, Boblitz N. Human pharmacological investigations during treatment of climacteric complaints with Cimicifuga racemosa (Remifemin®): No estrogen-like effects [Poster presentation]. 2nd International Congress on Phytomedicine, London, October 15–16, 1998.
9. Stoll W. Phytopharmaceutical influences atrophic vaginal epithelium. Double-blind study on Cimicifuga versus an estrogen preparation. Therapeutikon 1987;1:23–32.
10. Warnecke G. Using phyto-treatment to influence menopause symptoms. Med Welt 1985;36:871–4.
11. Düker EM, Kopanski L, Jarry H, Wuttke W. Effects of extracts from Cimicifuga racemosa on gonadotropin release in menopausal women and ovariectomized rats. Planta Medica 1991;57:420–4.
12. Liske E, Wüstenberg P. Therapy of climacteric complaints with Cimicifuga racemosa: a herbal medicine with clinically proven evidence [Abstract #98.0020]. Poster Presentation, 9th Annual Meeting of the North American Menopause Society, Toronto, Canada, September 16–9, 1998.
13. Kadota S, Li JX, Litt Y, et al. Effects of cimicifugae rhizome on serum calcium and phosphate levels in low calcium dietary rats and on bone mineral density in ovariectomized rats. Phytomed 1996/7;3:379–85.
14. Murray MT. The Healing Power of Herbs. Rocklin, CA: Prima Publishing, 1995, 376.
15. Bradley PR, ed. British Herbal Compendium, vol 1. Bournemouth, Dorset, UK: British Herbal Medicine Association, 1992, 34–6.
16. Blumenthal M, Busse WR, Goldberg A, et al. (eds). The Complete Commission E Monographs: Therapeutic Guide to Herbal Medicines. Boston, MA: Integrative Medicine Communications, 1998, 90.
17. Gruenwald J. Standardized black cohosh (Cimicifuga) extract clinical monograph. Quart Rev Nat Med 1998;Summer:117–25.
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The information presented in Healthnotes is for informational purposes only. It is based on scientific studies (human, animal, or in vitro), clinical experience, or traditional usage as cited in each article. The results reported may not necessarily occur in all individuals. For many of the conditions discussed, treatment with prescription or over-the-counter medication is also available. Consult your doctor, practitioner, and/or pharmacist for any health problem and before using any supplements or before making any changes in prescribed medications. Information expires July 2004.