Levonorgestrel

**Definition:** A synthetic progestational hormone with actions similar to those of PROGESTERONE and about twice as potent as its racemic or (+-)-isomer (NORGESTREL). It is used for contraception, control of menstrual disorders, and treatment of endometriosis.

**Tree numbers:** - D04.210.500.668.651.693.762.450

**Synonyms:** - 18,19-dinorpregn-4-en-20-yn-3-one, 13-ethyl-17-hydroxy-, (17alpha)-(-)- - D-Norgestrel - l-Norgestrel