Norethindrone

**Definition:** 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.

**Tree numbers:** - D04.210.500.668.651.693.651

**Synonyms:** - 19-Norpregn-4-en-20-yn-3-one, 17-hydroxy-, (17alpha)- - Ethinylnortestosterone - Norethisterone - Norpregneninolone