In this review, we discuss isoflavones, which are bioactive selective estrogen receptor modulators shown to have therapeutic efficacy in reducing bone resorption and improving menopause symptoms in women with estrogen deficiency. The European Food Safety Authority reached consensus that there "is no evidence of harm" of isoflavone supplements for peri- and post-menopausal women. Bioavailable isoflavone aglycones being rich in fermented sources are shown to have enhanced effects compared to glycosides, and isoflavones represent an effective and safe new treatment for oestrogen deficient bone loss and climacteric symptoms.