Effect of oral contraceptives on plasma androgenic steroids and their precursors.

Plasma dehydroepiandrosterone (DHEA), its sulfate ester (DHEAS), and androstenedione (A2), delta5-pregnenolone (delta5-P), and 17 alpha-hydroxypregnenolone were measured in women using estrogen-containing oral contraceptives and in female controls of similar age. All three androgenic steroids and their two C21 precursors were reduced in the oral contraceptive users compared with the controls. It is concluded that oral contraceptives cause a decrease in plasma DHEA, DHEAS, and A2, one possible mechanism for which is the inhibition of delta5-P synthesis from cholesterol.