The physiology of the perimenopausal years: a minireview.

Selected studies on the physiology of the perimenopausal years and the subtle transitional changes that occur up to the postmenopause are reviewed. Extraovarian sources of estrogen, which must be considered when recommending dosage of replacement therapy, are described. The effects of hormonal therapy on endogenous hormones and the important roles of progesterone and prolactin are highlighted. The collected evidence suggests that (a) the vasomotor disturbance and depression experienced by estrogen-deficient women are not psychosomatic disorders, (b) osteoporosis is preventable if estrogen therapy is initiated soon after cessation of ovarian function, and (c) administraton of a weak estrogen combined with a progestogen can effectively prevent or treat the difficulties experienced during the female climacteric.