Progestational activity of danazol in the human female subject

A progestational action of Danazol has not been reported in the human subject. Danazol administration for 1 month suppressed serum FSH and estradiol values, and the midcycle LH surge; ovulation promptly resumed after treatment. Administration to patients with polycystic ovarian disease resulted in increased LH values, elevated basal temperature, secretory findings in the endometrial biopsy, and menses. Ovarian biopsy did not document corpus luteum formation, and plasma progesterone did not rise. Administration of Danazol to an ovariectomized patients pretreated with estrogen resulted in an atypical endometrial secretory change. Clinical responses to Danazol may in part be explained by a progestational-like effect of the drug.