The molecule is a C21-steroid in which a pregnane skeleton carries a beta-hydroxy group at position 3, an alpha-hydroxy group at position 20 and a double bond between positions 4 and 5. It is a C21-steroid, a 3beta-hydroxy steroid and a 20-hydroxy steroid. It derives from a progesterone.
(3S,8S,9S,10R,13S,14S,17S)-17-[(1S)-1-hydroxyethyl]-10,13-dimethyl-2,3,6,7,8,9,11,12,14,15,16,17-dodecahydro-1H-cyclopenta[a]phenanthren-3-ol