Suppressive effect of an inhibitory LHRH analog on the gonadotropin response to LHRH in normal women.

Intramuscular administration of 90 mg of D-Phe-2, D-Trp-3, D-Phe-6-LHRH, an inhibitory analog of LHRH, to eight normal women diminished the gonadotropin response to 50 microgram of LHRH administered 3 and 6 hours later; however, an additional dose of LHRH 24 hours after the injection of the inhibitory analog elicited a significant secretion of both LH and FSH which in turn produced a significant release of estradiol. The menstrual cycle was disrupted in all eight cases and ovulation did not occur.