Selective inhibition by danazol of follicle stimulating hormone during the luteal phase.

In each of six healthy, normally menstruating women, serum oestradiol, progesterone, basal and post luteinizing hormone releasing hormone (LHRH) gonadotrophin measurements were made during the luteal phase of a normal cycle and in a subsequent cycle in which 800 mg of danazol was given daily from the fifth day after the presumptive date of ovulation. No differences in the serum oestradiol, progesterone, or basal gonadotrophin levels were detected, but there was a selective impairment of the follicle stimulating hormone response to LHRH. The implications of these findings are discussed.