The lack of effect of progestogen on bone

Several critical issues surround the possible effects of progestogens in postmenopausal women. No comparative studies of the effects of estrogen and progestogens on bone loss have been conducted to date, but a review of the available evidence suggests that endogenous progesterone has little effect on endometrial secretory homeostasis. The evidence also suggests that when used alone at normally prescribed dosages, progestogens have neither a direct effect on osteoporosis nor an additive effect when used as a component of hormone replacement therapy (HRT). The positive effects of HRT on bone seen in postmenopausal women are more likely a direct result of the estrogen component.