Black cohosh is a member of the buttercup family that is used to treat hot flushes during menopause. Black cohosh menopause treatments usually involve the underground root or stem of the plant that is ground up and made into teas, ointments or pills. A popular brand is Remifemin.
There have, to date, been two major studies centering around Remifemin. Trials before these two were generally small, of poor quality, and failed to provide evidence of a good enough standard. However, some did state that black cohosh menopause treatments were effective for hot flushes and several other aspects of the menopause.
The two major studies were randomized controlled trials (RCTs) that focused on whether Remifemin relieved hot flushes in menopausal women. The trials included 217 women, some of whom took a placebo and others who took the drug. Despite earlier positive results, there was no significant improvement over placebo. Indeed, one of the trials demonstrated a preference for the placebo over the actual drug. However, as these trials were of short duration, the long-term efficacy of black cohosh has not been established.
In addition, black cohosh menopause treatments have been found to have a toxic effect on the liver in certain patients. Several complaints of hepatitis and jaundice have been submitted, although these are unusual, and there were other circumstances that could have caused the hepatitis. The most common side effect of black cohosh menopause treatments is headaches and nausea.
Black cohosh menopause treatments have not been shown to be effective in the short term. There is no known mechanism by which black cohosh works to reduce hot flushes and other menopause-related conditions, which often confirms that the drug is no better than a placebo.