 It is the acetate ester of 17α-hydroxyprogesterone, as well as a parent compound of a number of progestins including chlormadinone acetate, cyproterone acetate, medroxyprogesterone acetate, and megestrol acetate.Chemical syntheses of OHPA have been described.In 1949, it was discovered that 17α-methylprogesterone had twice the progestogenic activity of progesterone when administered parenterally, and this finding led to renewed interest in 17α-substituted derivatives of progesterone as potential progestins.