Megestrol

**Definition:** A progestational hormone used most commonly as the acetate ester. As the acetate, it is more potent than progesterone both as a progestagen and as an ovulation inhibitor. It has also been used in the palliative treatment of breast cancer.

**Tree numbers:** - D04.210.500.745.432.531

**Synonyms:** - Pregna-4,6-diene-3,20-dione, 17-hydroxy-6-methyl- - 17-Hydroxy-6-methylpregna-3,6-diene-3,20-dione