Hormone-modulating herbs: implications for women's health.

Women in the United States are increasingly turning to botanical medicines to treat conditions throughout their life cycles. Many herbs traditionally used for women's health conditions have been found to contain phytoestrogens. Phytoestrogens and their metabolites can bind estrogen receptors and can have both estrogenic and anti-estrogenic effects. Many women are attracted to the idea of using phytomedicine as an alternative to hormone replacement therapy. It is unclear, however, whether these herbs are safe for women at risk for breast cancer or its recurrence. This paper considers the estrogenicity of herbs such as black cohosh (Cimicifuga racemosa) and the implications for women's health.