Origins
Black cohosh is a member of the buttercup family found in rich woods of the eastern deciduous forest from southern Ontario south to Georgia, west to Arkansas, north to Wisconsin. This perennial woodland plant likes the deep shade of moist hillsides, the home of other important medicinal plans such as goldenseal and ginseng. It has robust, three-divided leaves, with three-lobed terminal leaflets. The middle lobe of the sharply-toothed leaflets is the largest. The plant is little-noticed until it sends up its tall spikes of showy white flowers, three to eight feet tall. Petals are not to be seen; the chief feature is tufts of conspicuous stamens surrounding the pistil in the center. In begins blooming in May in the southern part of its range, continuing to flower into September in more northerly regions.

Black cohosh was first described by botanists in 1705. By 1732, it had been introduced into English gardens as a hardy ornamental perennial. To this day, it is more widely grown in European gardens than in America. The root is the part of the plant used in herbal traditions. Most of the root is wild-harvested, while some is grown commercially in Europe.

The genus Cimicifuga includes eighteen species, one of which is native to Europe, six from North America, and the remainder from northeast Asia. Collectively, they are commonly known as bugbanes, primarily referring to the single native European species, C. europaea and an Asian representative C. foetida, which have strong, unpleasant smelling herbage, earning it a reputation as an insect-repelling plant. The genus name Cimicifuga, itself, honors this olfactory observation. It comes from the Latin cimex meaning bug (specifically the bed bug Cimex lectularius) and fugare "to drive-away" in reference to the insect-repelling attributes. These species are also known by the names bugwort or bugbane. They have been used independently as insect repellents throughout their extensive ranges from India to western Europe to eastern Siberia. The herbage of the American black cohosh does not possess a strong odor.

Historical Development
American Indian groups of eastern North America were using the root of black cohosh to treat female conditions and for rheumatism, long before Europeans landed on American shores. The Delaware, moved to the Indian Territories of modern Oklahoma a century ago, used black cohosh in combination with other herbs as a female tonic. The Iroquois of New York used a strong tea of the root as a foot bath, soaking the feet while bathing sore, stiff areas of the body to treat rheumatism. The Cherokee are said to have used the roots to treat rheumatism and various female conditions. They also valued it as a tonic and diuretic. Early medical authors note that use of the plant was learned from native Americans.

The importance of black cohosh as a medicinal plant was recognized in the first works on American herbs, dating back to 1801. The root was an important folk medicine among American Indian groups and early settlers for menstrual irregularities and as an aid in childbirth. It was widely prescribed by physicians in nineteenth century America, where it had a great reputation as an anti-inflammatory for arthritis and rheumatism, and played an important role for normalizing suppressed menses, painful or difficult menses, and to relieve pain after childbirth. It was also used for nervous disorders. The root was an official drug of the United States Pharmacopoeia from 1820 to 1926.

In historical works, information on the herb can be found under several names. Early editions of the United States Pharmacopoeia gave its official name as "black snakeroot," a name that persisted in medical books into the 1890s. Eclectic medical practitioners of the late nineteenth and early twentieth centuries knew it by the name "macrotys" both a botanical and common name that was never widely recognized, and is lost in obscurity.

It was the eclectics who championed the use of black cohosh, particularly Dr. John King, (1813-1893), who also first brought Echinacea to the attention of the medical community. Black cohosh was more important to King than Echinacea, since he was a professor of obstetrics at the old Eclectic medical college in Cincinnati (which closed its doors in 1943). He spoke about black cohosh to his students as his "favorite remedy. " He had used it in his own clinical practice from 1832 until his death, as an important remedy in both acute and chronic cases of rheumatism and related inflammatory conditions, plus various lung and nervous affections. King recognized it as his primary treatment "in abnormal conditions of the principal organs of reproduction in the female."

If King had not been such a strong proponent of the herb, it may have faded away into obscurity. Like several important herbs, such as Echinacea and saw palmetto, in the early part of this century, the eclectics' extensive use and advocacy of black cohosh attracted the attention of the German medical community. As use of herbs faded in American medicine by the 1930s, the Germans picked-up the reins and catapulted these herbs into modern use. Once again, we turn to Germany for modern experience with this useful traditional American Indian remedy.

Modern Use
Scientific research on black cohosh began with investigations of its chemistry in the early twentieth century. Using the comparatively crude isolation methods of the day, chemists found phytosterin, isoferulic acid, salicylic acid, sugars, tannins and fatty acids in the roots. A study published in 1944 first attributed estrogenic-like activity to the roots in laboratory experiments with mice. In the 1950s and 60s further chemical work identified glycosides such as acetin, cimicifugoside, and 27 deoxyacteine as compounds that may contribute to the root's effects on female reproduction. In the early 1980s an isoflavone called, formononetin was also identified. Clear attribution of biological activity to a single chemical component remains illusive. It is believed that at least three different chemical fractions soluble in alcoholic extracts may contribute to positive benefits in the treatment of menopausal symptoms.

By the mid 1950s sufficient scientific evidence, coupled with extensive clinical experience, made black cohosh preparations widely accepted and prescribed by German gynecologists, primarily as a an alterative to hormone treatment in menopausal disorders. By that time, hormonal replacement therapies were already recording unwanted side effects in a large number of patients. By 1962 at least 14 clinical studies (though not controlled clinical studies in the modern sense) had been published on the use of black cohosh products in over 1500 patients. These studies, some over 40 years old, began to establish clear scientific evidence for the safety and effectiveness of black cohosh in the treatment of premenopausal and menopausal symptoms including a reduction in the severity and duration of hot flashes along with an improvement of depressive moods.

Clinical studies
Today in Germany, black cohosh preparations are used in the treatment of menopause to improve symptoms such as hot flashes, depression and sleep disturbance. In 1985, German researchers found that black cohosh produced an effect on serum concentrations of pituitary hormone levels, including a significant and selective reduction of luteinizing hormone (while not significantly effecting levels of prolactin and follicle stimulating hormone). Hot flashes have been linked to a significant spike in the release of luteinizing hormone. The study provided a way to measure the endocrinological, particularly estrogenic effects, of black cohosh. A follow-up study failed to identify a single chemical component responsible for the luteinizing hormone suppressing activity, leading researchers to believe that synergistic effects of several chemical fractions were involved in the biological activity, competing with estradiol for binding sites on receptor proteins.

Recent clinical studies have shed further light on the herb's effects. A 1982 an open multi-center German clinical study involving data on 629 patients from 131 general practitioners and gynecologists was published. The researchers found that after six to eight weeks of treatment, 80 percent of patients had beneficial effects. In over 49 percent of volunteers there was dramatic relief in reduction of hot flashes, sweating, headache, vertigo, palpitation and tinnitus, while over 39 percent reported significant reductions of these symptoms, along with a lessening of nervousness, irritability and depression. Side effects (unspecified gastrointestinal problems) were reported for seven percent of the women. None of the side effects were serious enough to discontinue treatment.

A 1987 German double blind study compared estrogen replacement therapy with black cohosh for three months in eighty women. Thirty received a black cohosh extract (8 mg per day), 30 received black cohosh, and 20 volunteers received placebo. The black cohosh preparation was well-tolerated and produced significant improvement in the test parameters, which included menopausal symptoms as measured by the Kupperman Menopausal Index, depressive symptoms as measured by the Hamilton Anxiety Scale, as well as its effect on vaginal epithelium cells. The author concluded that black cohosh not only produced safe and efficacious results, but compared to estrogen replacement therapy, is suitable as a treatment of choice in menopausal symptoms.

A 1988 German clinical study compared treatment with three different estrogen therapies and an extract of black cohosh in 53 women (under 40 years of age). Many had experience surgical removal of an ovary leading to development of menopausal-like symptoms. Treatment with the black cohosh extract was found to be comparable to treatment with the three conventional drug preparations tested. The authors concluded that in cases where conventional hormone therapy is contraindicated, the plant extract is the therapy of choice.

In 1991 another German research group conducted a study involving 110 menopausal women. They demonstrated for the first time in a clinical trial that the extract selectively suppresses luteinizing hormone secretion in menopausal women, and further confirms an estrogenic effect of the alcoholic fractions of black cohosh root.

These limited clinical studies provide encouraging results setting the stage for further, larger scale controlled clinical studies in the future.

Black Cohosh Today
Used in Europe for over 40 years, with experience in over 1.5 million cases, black cohosh is again becoming known in its native land as a possible alternative for reducing unpleasant symptoms associated with menopause. Efficacy and safety are confirmed by long-term clinical experience, as well as recent controlled clinical studies, along with acute toxicity studies which help to corroborate its safety.

In Germany, black cohosh is covered by a positive monograph of the German Commission E. Products can be labeled for "premenstrual discomfort, dysmenorrhea or climacteric (menopausal) neurovegetative ailments." Reported activities are an estrogen-like action, binding to estrogen receptors and suppression of luteinizing hormone. The German authorities suggest a daily dose of a liquid extract (with 40-60 percent alcohol) equivalent to 40 mg of the dried root. Typically, the product on which the vast majority of studies have been conducted is a concentrated extract delivered at a dose of 8 mg (4 mg twice per day). Transient gastric discomfort is the only side effect reported. Presumably because long-term toxicity studies have not been conducted, duration of use is limited to six months.

Black cohosh will become of increasing interest to women looking for an alternative to estrogen therapy in the treatment of menopausal symptoms. Not only is it widely used in Europe, black cohosh and related species have a long history of use in both Asia and North America. Among women's herbs, black cohosh is the most important rising star.

Further reading

1. Blumenthal M., et al, eds. S. Klein and R. S. Rister, translators. German Commission E Monographs: Therapeutic Monographs on Medicinal Plants for Human Use. Austin, Texas: American Botanical Council. In press, 1998.
2. Bradley, P. R. British Herbal Compendium Vol. 1. A Handbook of Scientific Information on Widely Used Plant Drugs.. Dorset, U.K. British Herbal Medicine Association, 1992.
3. Brown, D. Herbal Prescriptions for Better Health. Rocklin, Calif. Prima Publishing, 1995
4. Düker, E.-M.,et al. 1991. Effects of Extracts from Cimicifuga racemosa on Gonadotropin Release in Menopausal Women and Overiectomized Rats. Planta Medica, 1991, 57:420-424.
5. Harnischfeger, G. and H. Stolze. Black Cohosh. Notabene Medici 1980, 10:446-50.
6. Jarry, H. and G. Harnischfeger. Studies on the endocrine effects of the contents of Cimicifuga racemosa: 1. Influence on the serum concentration of pituitary hormones in Ovariectomized rats. Planta Medica. 1985, 51(1): 46-49.
7. Lloyd, J.U. and C.G. Lloyd. Drugs and Medicines of North America. 2 vols. Cincinnati: J.U. & C.G. Lloyd, 1884-85.
8. Stoll, W. Phytopharmacon Influences Atrophic Vaginal Epithelium. Double-blind Study-Cimicifuga vs. Estrogenic Substances. Therapeuticum. 1987, 1:23-31.
9. Stolze, H. An Alternative to Treat Menopausal Complaints. Gyne. 1982, 3:14-16.