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
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3 StarsReliable and relatively consistent scientific data showing a substantial health benefit.
2 StarsContradictory, insufficient, or preliminary studies suggesting a health benefit or minimal health benefit.
1 StarFor an herb, supported by traditional use but minimal or no scientific evidence. For a supplement, little scientific support.
This supplement has been used in connection with the following health conditions:
20 mg of a highly concentrated herbal extract taken twice per day
Some, but not all, double-blind trials support the usefulness of black cohosh for women with hot flashes associated with menopause.4 In a three-month study of postmenopausal women, 40 mg per day of an extract of black cohosh was as effective as estrogen therapy in the treatment of hot flashes.5 A review of eight trials concluded black cohosh to be both safe and effective.6 However, one double-blind trial found that black cohosh is ineffective as a treatment for menopausal symptoms.7 Many doctors recommend 20 mg of a highly concentrated extract taken twice per day; 2 to 4 ml of tincture three times per day may also be used.
In a double-blind study of postmenopausal women who were experiencing psychological symptoms, a combination of black cohosh and St. John's wort was significantly more effective than a placebo in improving both menopausal symptoms and depression. The product used in this study contained (per tablet) black cohosh standardized to 1 mg of triterpene glycosides and St. John's wort standardized to 0.25 mg of hypericin. The amount taken was two tablets twice a day for eight weeks, followed by one tablet twice a day for eight weeks.8
Menopause and Depression (St. John’s Wort)
Two tablets twice a day for 8 weeks, then one tablet twice a day for 8 weeks, each tablet supplying 1 mg of triterpene glycosides from black cohosh and 0.25 mg of hypericin from St. John's wort
In a double-blind study of postmenopausal women who were experiencing psychological symptoms, a combination of black cohosh and St. John's wort was significantly more effective than a placebo in improving both menopausal symptoms and depression. The product used in this study contained (per tablet) black cohosh standardized to 1 mg of triterpene glycosides and St. John's wort standardized to 0.25 mg of hypericin. The amount taken was two tablets twice a day for eight weeks, followed by one tablet twice a day for eight weeks.9
Refer to label instructions
Black cohosh has a history as a folk medicine for relieving menstrual cramps. Black cohosh can be taken in several forms, including crude plant, 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, though they have primarily been researched for use with menopausal women suffering from hot flashes. The recommended amount is 20–40 mg twice per day.10 The best researched form provides 1 mg of deoxyactein per 20 mg of extract. Tinctures can are also used (2–4 ml three times per day).11 The Commission E Monograph recommends black cohosh be taken for up to six months, and then discontinued.12
Refer to label instructions
Black cohosh has been shown to improve bone mineral density in animals fed a low calcium diet,13 but it has not been studied for this purpose in humans.
Refer to label instructions
Black cohosh is approved in Germany for use in women with PMS.14 This approval appears to be based on historical use as there are no modern clinical trials to support the use of black cohosh for PMS.
Traditional Use (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.3
How It Works
How It Works
Black cohosh contains several ingredients, including triterpene glycosides (for example, acetin and 27-deoxyactein) and isoflavones (for example, 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 studies15, 16 and a human clinical trial17 suggested that black cohosh had some estrogen activity in the body and also decreased LH secretions. However, more recent animal studies18 and a clinical trial19 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.20, 21 A review of eight clinical trials found black cohosh to be both safe and effective for symptomatic relief of menopausal hot flashes.22 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.23 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.24 Human studies have not confirmed this action.
How to Use It
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.25 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.26 According to the German Commission E Monographs, black cohosh can be taken for up to six months, and then it should be discontinued.27
Interactions with Supplements, Foods, & Other Compounds
At the time of writing, there were no well-known supplement or food interactions with this supplement.
Interactions with Medicines
As of the last update, we found no reported interactions between this supplement and medicines. It is possible that unknown interactions exist. If you take medication, always discuss the potential risks and benefits of adding a new supplement with your doctor or pharmacist.
The Drug-Nutrient Interactions table may not include every possible interaction. Taking medicines with meals, on an empty stomach, or with alcohol may influence their effects. For details, refer to the manufacturers’ package information as these are not covered in this table. If you take medications, always discuss the potential risks and benefits of adding a supplement with your doctor or pharmacist.
Black cohosh should not be used by pregnant or breast-feeding women.28 Very large amounts (over several grams daily) of this herb may cause abdominal pain, nausea, headaches, and dizziness.
There is one case report of a woman developing autoimmune hepatitis while using black cohosh.29 A cause–effect relationship is in doubt, however, because the hepatitis did not resolve after black cohosh was discontinued. A few cases have also been reported in which severe liver failure was attributed to the use of black cohosh.30 While a cause–effect relationship is difficult to prove, and while such a side effect appears to be rare, people taking black cohosh should be alert to signs of possible liver disease, such as nausea, loss of appetite, fatigue, and tan-colored urine. Black cohosh is not a substitute for hormone replacement therapy during menopause.
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. Liske E. Therapeutic efficacy and safety of Cimicifuga racemosa for gynecological disorders. Advances Therapy 1998;15:45–53.
5. Nappi RE, Malavasi B, Brundu B, Facchinetti F. Efficacy of Cimicifuga racemosa on climacteric complaints: a randomized study versus low-dose transdermal estradiol. Gynecol Endocrinol 2005;20:30–5.
6. Lieberman S. A review of the effectiveness of Cimicifuga racemosa (black cohosh) for the symptoms of menopause. J Womens Health 1998;7:525–9.
7. Newton KM, Reed SD, LaCroix AZ, et al. Treatment of vasomotor symptoms of menopause with black cohosh, multibotanicals, soy, hormone therapy, or placebo: a randomized trial. Ann Intern Med 2006;145:869–79.
8. Uebelhack R, Blohmer JU, Graubaum HJ, et al. Black cohosh and St. John's wort for climacteric complaints: a randomized trial. Obstet Gynecol 2006;107:247–55.
9. Uebelhack R, Blohmer JU, Graubaum HJ, et al. Black cohosh and St. John's wort for climacteric complaints: a randomized trial. Obstet Gynecol 2006;107:247–55.
10. Murray MT. The Healing Power of Herbs. Rocklin, CA: Prima Publishing, 1995, 376.
11. Bradley PR, ed. British Herbal Compendium, vol 1. Bournemouth, Dorset, UK: British Herbal Medicine Association, 1992, 34–6.
12. 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.
13. Kadota S, Li JX, Li HY, 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 1996/97;3(4):379–85.
14. Blumenthal M, Busse WR, Goldberg A, et al., eds. The Complete German Commission E Monographs: Therapeutic Guide to Herbal Medicines. Austin: American Botanical Council and Boston: Integrative Medicine Communications, 1998, 90.
15. 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.
16. 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.
17. 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.
18. Einer-Jensen N, Zhao J, Andersen KP, Kristoffersen K. Cimicifuga and Melbrosia lack estrogenic effects in mice and rats. Maturitas 1996;25:149–53.
19. 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.
20. Stoll W. Phytopharmaceutical influences atrophic vaginal epithelium. Double-blind study on Cimicifuga versus an estrogen preparation. Therapeutikon 1987;1:23–32.
21. Warnecke G. Using phyto-treatment to influence menopause symptoms. Med Welt 1985;36:871–4.
22. 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.
23. 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.
24. 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.
25. Murray MT. The Healing Power of Herbs. Rocklin, CA: Prima Publishing, 1995, 376.
26. Bradley PR, ed. British Herbal Compendium, vol 1. Bournemouth, Dorset, UK: British Herbal Medicine Association, 1992, 34–6.
27. 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.
28. Gruenwald J. Standardized black cohosh (Cimicifuga) extract clinical monograph. Quart Rev Nat Med 1998;Summer:117–25.
29. Cohen SM, O'Connor AM, Hart J, et al. Autoimmune hepatitis
associated with the use of black cohosh: a case study. Menopause 2004;11:575–7.
30. Levitsky J, Alli TA, Wisecarver J, Sorrell MF. Fulminant liver failure associated with the use of black cohosh. Dig Dis Sci 2005;50:538–9.
The information presented in Aisle7 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 June 2014.
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