Ovarian function following a single administration of depo-medroxyprogesterone acetate (DMPA) at different doses

The effects of a single administration of depo-medroxyprogesterone acetate (DMPA) at different doses upon ovarian function was studied in a group of healthy ovulating Mexican women. Single doses of DMPA of 25, 50, 100, and 150 mg were intramuscularly administered. Ovarian function was assessed by the measurement of the serum levels of 17 beta-estradiol and progesterone in blood samples drawn twice weekly for 6 months after DMPA administration. The results disclosed that ovulation was inhibited in all cases for at least 3 months following DMPA administration even at the lowest dose, whereas the return of luteal function exhibited a significant positive correlation with the dose of DMPA administered. As expected, follicular activity preceded that of luteal function in all subjects. A correspondence between serum medroxyprogesterone concentrations and ovarian function was found. The overall data indicated that the currently used contraceptive formulation (150 mg) is well above the effective pharmacologic range, and suggested that the dose can be substantially reduced without losing its anovulatory potency.