More than forty years ago a natural phenolic estrogenic compound was found in P. mirifica that was identified and named, miroestrol [3,14,17,18-beta-tetrahydroxymiroestrol-1,3,5(10),7-tetraen-15-one]. Unlike such well known phytoestrogens as genistein and daidzein, miroestrol was structurally similar to endogenous estrogen found in humans, thereby accounting for its reported estrogenic-like properties.