Plasma Hormone Concentrations in Women Receiving Steroid Contraceptives

Summary Plasma concentrations of progesterone, oestradiol, testosterone and corticosteroids have been measured by competitive protein binding methods in blood specimens taken from large groups of untreated women and others taking various combined‐ type oral contraceptive proparations. A third group receiving depot injections of medroxyprogesterone acetate was also studied. In other experiments, plasma steroid hormone concentrations were measured before and after treatment by oral or depot contraceptives. Oral contraceptives reduced plasma levels of progesterone and oestradiol to approximately those seen in the follicular phase of untreated women; in contrast, levels of testosterone and corticosteroids, both free and protein‐bound, were markedly increased. The depot preparation had a similar action on progesterone and oestradiol, but did not increase testosterone or cortisol concentrations.