The relative effects of progesterone and progestins in hormone replacement therapy.

Hormone replacement therapy (HRT) was initially given to protect women against osteoporosis and alleviate menopausal symptoms, such as hot flashes, depression, sleep disturbances, and vaginal dryness. In view of the understanding of oestrogen deficiency as a major trigger for the acceleration of cardiovascular risk after menopause, HRT may also be proposed as a substantial beneficial cardioprotective agent. Progestins, which may be added to oestrogen in combined HRT to reduce the risk of uterine malignancy, have a number of potential adverse effects on the cardiovascular system which could even attenuate the benefit of unopposed oestrogen replacement therapy in post-menopausal women.