Botanical name: Cimicifuga racemosa
© Steven Foster
Parts used and where grown
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):
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.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.
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.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
Are there any side effects or interactions?
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.
There is one case report of a woman developing autoimmune hepatitis while using black
cohosh.18 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.19
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.
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,
2. Castleman M. The Healing Herbs. Emmaus, PA: Rodale Press,
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.
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.
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.
18. 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.
19. 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.