What is "gestrinone"

n. A synthetic steroid hormone that acts as an antiprogestin and also has some androgenic activity.

Gestrinone ( INN, USAN, BAN) (brand names Dimetriose, Dimetrose, Nemestran), also known as ethylnorgestrienone (i.e., ethyl derivative of norgestrienone), is a synthetic steroid of the 19-nortestosterone group that is marketed in Europe, Australia, and Latin America, though not the United States, and is used primarily in the treatment of endometriosis. It is a potent mixed progestogen and antiprogestogen (i.e., partial agonist of the progesterone receptor (PR) or selective progesterone receptor modulator (SPRM)), an antigonadotropin, a mild androgen and anabolic steroid, and a functional antiestrogen. Gestrinone is described as similar in action and effect to danazol, which is also used in the treatment of endometriosis, but is reported to have fewer androgenic side effects in comparison. Because of its anabolic effects, the use of gestrinone in competition has been banned by the International Olympic Committee.