Black Cohosh (Cimicifuga Racemosa) contains Isoflavones (phytoestrogens) that binds to estrogen receptors and have mild estrogen activity.Black Cohosh (Cimicifuga racemosa) is a tall stately plant native to the eastern forests of the United States and Canada. This herb was named Black because its dark roots, and Cohosh is Algonquian for "rough", another refrence to its roots.Early American settlers found that Black Cohosh was widely used by American Indian Tribes. Specifically, the hard, knotty rootstock or rhizome, which was used for a variety of health purposes. The Indians used it externally on the skin and internally for the nutritional needs of women. This explains why it was also known as "Squaw Root".