•  PMS

Black cohosh (Cimicifuga Racemosa ) is a large, flowering plant that grows in the forests east of the Mississippi. Native Americans used its black roots to treat smallpox, rattlesnake bites, yellow fever, and a whole range of gynecological complaints. Black cohosh was also the main ingredient -- after alcohol, that is -- in Lydia E. Pinkham's Vegetable Compound, touted at the turn of the century as the ultimate elixir for the "Change of Life" and all "those painful Complaints and Weaknesses so common to our best female population."

It isn't clear whether Lydia and the Cherokee Nation were right about the benefits of black cohosh for the "female population." Germany's Ministry of Health has endorsed this traditional American remedy as an effective treatment for PMS, menstrual cramps, and various menopause-related complaints, including hot flashes and vaginal dryness, though studies of the effectiveness of black cohosh have produced varying results.

In a 2006 German trial of over 300 women, researchers found black cohosh to be safe and effective in relieving complaints related to menopause when study participants took it with St. John’s wort. In 2005, researchers at the University of Illinois at Chicago reviewed studies over the past 38 years of alternative therapies for menopause and found black cohosh to be safe and effective in relieving hot flashes and possibly mood disorders. However, an earlier study published in the Journal of Clinical Oncology found black cohosh extract did not reduce hot flashes in breast cancer survivors. And in 2002, while researchers at Columbia University reviewed 29 studies of alternative therapies for menopause and found black cohosh to be effective in relieving hot flashes, they warned that the safety of using the herb for a long time had not been determined.

Currently we don't understand how black cohosh might work to relieve hot flashes. Some evidence suggests that it suppresses the release of luteinizing hormone, which normally surges during menopause in response to plunging estrogen levels, but other evidence suggests this is not the case. The herb was long considered by some experts to be a "phytoestrogen" or plant estrogen. However, recent studies suggest that it has very little, if any, estrogenic effect and that it may in fact block estrogen. Until we know more, women whose doctors have advised them to avoid estrogen would be wise to avoid black cohosh as well.

German studies have reported few side effects from black cohosh other than occasional stomach upset, although the herb's effects on women have not been studied for longer than six months. In recent years, however, there have been several case reports of liver poisoning resulting from the use of this supplement (although the patients were usually taking other herbs as well). In 2006, the journal Liver Transplantation documented a case of liver failure resulting in a liver transplant after the use of black cohosh. Although clinical trials have not raised safety issues, at this point the possibility of liver poisoning by black cohosh “cannot be ruled out,” according to Pharmacist’s Letter.

Because of its possible effects on hormone levels, don't take black cohosh if you're pregnant, breastfeeding, or on birth control pills. A recent study by Yale researchers found that black cohosh increased the toxicity of certain chemotherapy drugs when tested on laboratory-grown breast cancer cells, so women undergoing chemotherapy should be especially careful to check with their doctors if they're thinking of taking it. Women who have existing liver disease, use alcohol heavily, or take other drugs that could harm the liver should avoid black cohosh, according to the Pharmacist’s Letter. In fact, it's always a good idea to check with your doctor before you take any over the counter supplement to be sure it won't interact with any medications you're taking.

Symptoms of liver damage can appear in the form of acute or chronic liver disease such as viral hepatitis or blockage of the bile ducts. A person with liver damage may develop any or several of these symptoms: fever, abdominal pain, jaundice, chills, fatigue, itchy skin, aching joints, loss of appetite, or nausea. If you find yourself experiencing these symptoms, you should see your doctor immediately.

You can find Remifemin, the same product that was used in the German trials, in most health-food stores or pharmacies. Women in the studies took 40-80 milligrams of black cohosh Remifemin twice daily. Due to an improved extraction process, the suggested dose has been reduced to 20 mg. twice daily.

References

First published July 14, 1999
Last updated January 23, 2008
Copyright © 1999 Consumer Health Interactive

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