Progesterone 5G. Progesterone, A substrate of Cytochrome P450 3A4, CAS Number: 57-83-0, Molecular Formula: C21H30O2, Molecular Weight: 314. 5, Purity: greater than or equal to 98%, Appearance: Crystalline solid, Storage: Conditions -20 deg C, Synonym: pregn-4-ene-3, 20-dione, Size: 5G