Evidence is required for the optimal management of young women with premature ovarian failure, either as a result of childhood cancer treatment or for other reasons. These women are currently offered combined sex steroid replacement in the convenient form of the oral contraceptive pill, or hormone replacement therapy, designed for older women after the menopause. These preparations are not designed to achieve physiological replacement of oestrogen or progesterone, either in dosage or in biochemical structure - many preparations using synthetic derivatives. These younger women who have differing metabolic and psychological requirements are looking to a future of 30 or more years of replacement. The optimal mode of SSR is not known for young women with premature ovarian failure, however there is concern that current regimens may be inadequate for optimal skeletal and cardiovascular health.