About Danazol Synthetic steroid ethisterone derivative, an isoxazole of testosterone, Synthetic Androgen. Mechanism of Action of Danazol It is an orally effective ethisterone derivative- attenuated androgen which suppresses gonadotropin secretion from pituitary in both men and women and results in inhibition of testicular and ovarian function. It suppresses gonadal function directly and by inhibiting steroidogenic enzymes. It causes endometrial atrophy and amenorrhoea. It also decreases the rate of growth and nodularity of abnormal breast tissue in fibrocystic breast disease. It has mild androgenic, anabolic, and progestational activity. Androgenic effects increases the levels of C1 and C4 components of complements which reduce frequency and severity of attacks associated with hereditary angioedema. Indications for Danazol 1.Endometriosis 2.Fibrocystic breast disease 3.Gynaecomastia 4.Menorrhagia 5.Hereditary angioedema.