Found this on Breast cancer .org
Also known as: baneberry, bugwort, black snakeroot, cimicifuga, rattle root, squaw root, RemiSure™, Remifemin®.
Potential uses: It's thought that black cohosh can relieve menopausal symptoms, especially hot flashes.
Usual dose: An extract containing 1 milligram of active ingredient taken twice per day.
Are there any risks? Black cohosh may be safe at recommended doses, but possible side effects include liver damage and autoimmune hepatitis.
What does the research show? One clinical trial in women with breast cancer showed that black cohosh gave no more relief from hot flashes than a placebo (sugar pill). Preliminary work on individual cells suggests black cohosh may act on estrogen receptors in some way and is associated with lowered breast cancer risk. A 2007 study involving nearly 2,500 women found that use of black cohoch reduced the risk of breast cancer, but this was the first known report of such an effect. Until more studies are done, people who have been diagnosed with breast cancer or who are at high risk for breast cancer should speak with their doctors if they are considering black cohosh.
The side effects alone would keep me from using this but there might be some merit to it. Like they said there was only one study showing it possibly helped with Bcancer so the jury is still out on this one.