We review studies that propose follicle-stimulating hormone (FSH) as a physiologic stimulator of osteoclastic bone resorption. We hypothesize that, in addition to low estrogen, a rising FSH contributes to the increased bone resorption and bone loss in hypergonadism. This is of particular relevance to the perimenopausal transition, wherein profound bone loss is accompanied by trabecular perforations in the face of high FSH and normal estrogen levels. Potential therapeutic implications include the development of antagonists to both circulating FSH and its osteoclastic receptor.