What is "danazol"

n. A derivative of the synthetic steroid ethisterone, a modify testosterone, formerly used to treat endometriosis.

Danazol ( INN, USAN, BAN, JAN) (brand names Danocrine, Danol, Danazol, Danatrol, Danoval, Cyclomen, many others), also known as 17α-ethinyl-17β-hydroxy-4-androsten-[2,3-d]isoxazole, is a synthetic steroid that is used primarily in the treatment of endometriosis and is marketed widely throughout the world. It is the derivative of ethisterone (17α-ethynyltestosterone) where the 3- ketone is replaced with a 2,3- isoxazole moiety. Danazol was approved by the US Food and Drug Administration as the first drug to specifically treat endometriosis in 1971. Although effective for endometriosis, its use is limited by its masculinizing side effects. Since their introduction, danazol has largely been replaced by gonadotropin-releasing hormone (GnRH) agonists in the treatment of the condition.