Megestrol [Chemical/Ingredient] Megestrol C25950 6703 Megestrol Pregna-4,6-diene-3,20-dione, 17-hydroxy-6-methyl- 17-Hydroxy-6-methylpregna-3,6-diene-3,20-dione. 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. M0013296 N0000007795 C0025175 D008535 Megestrol Pregnadienes [Chemical/Ingredient]