Estrogen replacement therapy: effects on the endogenous androgen milieu

To review the impact of exogenous estrogen replacement therapy (ERT) on the production, binding, and metabolism of ovarian and adrenal androgens.

Review of the scientific literature from January 1966 through June 2001 using MEDLINE.

Although no precipitous drop in androgen production is apparent at the time of the menopause, androgens decrease slowly and progressively from early adulthood until old age. The impact of aging and of estrogen replacement therapy, particularly oral ERT, significantly reduces androgen bioavailability after menopause. The combined effects of reduced production with aging and the pharmacologic effects of oral ERT dramatically reduce the endogenous bioavailable androgen milieu. These changes may have adverse clinical implications for susceptible individuals.