Black cohosh is a popular herb for alleviating the symptoms of menopause, particularly hot flushes. This herb has a long history of being used this way, but until recently, the scientific community did not know why it worked.

But research from the University of Illinois in Chicago discovered a possible mechanism. It appears that elements of the ethanol extract of black cohosh bind to some of the opiate receptors in women, the mu-opiate receptors. These opiate receptors are involved in the regulation of body temperature, pain control, and immune response. Though they are called opiate receptors, types of molecules other than opiates (like the class A drugs such as morphine) can bind to, and activate, them.

“The opiate receptor system affects several aspects of female reproductive neuroendocrinology, such as the control of sex hormones,” wrote lead author Mee-Ra Rhyu.

Hot flushes are suggested to be the result of flawed body core temperature settings, controlled by the central nervous system (CNS), which in turn is regulated by the opiate system, said the researchers. (NutraIngredients.com)

The way the black cohosh is extracted may be the key here. Different methods of getting the active constituents out of herbs exist. The ones used depends on the types of phyto-chemicals you’re trying to extract. Water infusions don’t extract alkaloids, for example. It seems significant that an ethanol extraction was used, though the types of phyto-chemicals believed to drive this effect of black cohosh aren’t mentioned in the article I read.

More information on black cohosh and menopause herbs can be found here.