19-Norpregn-4-en-20-yn-3-one, 17-hydroxy-, (17alpha)-
Norethindrone, (1 beta)-Isomer
A synthetic progestational hormone with actions similar to those of PROGESTERONE but functioning as a more potent inhibitor of ovulation. It has weak estrogenic and androgenic properties. The hormone has been used in treating amenorrhea, functional uterine bleeding, endometriosis, and for contraception.