Native Americans originally discovered black cohosh as a remedy for menstrual cramps and menopause symptoms. Today, doctors in Germany treat these same symptoms with the herb, and in this country, black cohosh is a popular natural remedy for hot flashes and other symptoms of menopause.
"There's very good data in the literature that shows black cohosh does help hot flashes," says Mary Jane Minkin, MD, an ob-gyn in private practice in New Haven, Conn., and professor of obstetrics and gynecology at Yale University School of Medicine. This is some of the key research:
In a study published in Obstetrics & Gynecology, 304 women experiencing menopausal symptoms were given either black cohosh or a placebo for 12 weeks. The herb was more effective than the placebo and provided relief comparable to hormone replacement therapy. Black cohosh was most effective when taken early, just after the onset of symptoms.
In a study published in Gynecological Endocrinology, 64 women were given either black cohosh or an estrogen patch for three months. Improvement in hot flashes, anxiety, and depression was comparable for both types of treatment. Unlike women using the estrogen patch, those taking the herb also experienced increased HDL ("good") cholesterol. Both treatments reduced LDL ("bad") cholesterol.
A review of research, published in Menopause: Journal of the North American Menopause Society, found that black cohosh is a safe and effective alternative to conventional hormone replacement therapy. Based on data from 2,800 patients, this study found that the herb does not affect levels of hormones in the body or increase risk for cancers. The majority of studies tested the proprietary extract Remifemin.
A study of 244 Asian women, published in Maturitas, found that Remifemin was as effective as conventional hormone replacement therapy and that the herb was safer.
Uncovering the Herb's Magic
Although scientists have yet to fully understand exactly how black cohosh works, research has shown that it is not a plant source of estrogen. According to Eckehard Liske, PhD, lead author of a study of Remifemin, published in The Journal of Women's Health and Gender-Based Medicine: "The product reduces menopause symptoms such as hot flashes, mood swings, night sweats, and occasional sleeplessness without affecting hormone levels or specific cell lines associated with some female cancers."
Other studies, published in the Journal of Agricultural and Food Chemistry, found that black cohosh influences the brain's temperature-control mechanisms. One study found that the herb affects serotonin receptors that influence body temperature. Another study found that black cohosh may act on the brain's opiate receptors, which affect levels of sex hormones and regulate pain, temperature, and appetite. Because of this mechanism, which is quite different from hormone replacement therapy, it would seem that black cohosh may provide relief without the risks of conventional hormone therapy, which include higher odds of female cancers, heart attack, and stroke.
How to Use Black Cohosh
To treat hot flashes or other symptoms related to menopause or perimenopause, as well as PMS or menstrual cramps, follow the product label directions. If improvement doesn't occur within one to two months, discuss other options with your physician, and check if medications, such as antidepressants, or other conditions, such as diabetes, could be triggering hot flashes. There are no known interactions between black cohosh and medications. To maximize benefits of the herb, eat a diet low in sugar and rich in natural foods, and exercise regularly.
Black cohosh is widely available at health food stores, as a single supplement, and in combinations designed to ease menopause symptoms. Some high-quality formulas to consider include Vitanica Black Cohosh Cimicifuga Extract Plus, Enzymatic Therapy Remifemin, Pure Essence Labs ProFema (a blend of herbs for menopause symptoms), and Natural Factors Black Cohosh Extract.