Ethisterone is a progestogen, or an agonist of the progesterone receptors. It has about 44% of the affinity of progesterone for the progesterone receptor. The medication is described as a relatively weak progestogen, similarly to its analogue dimethisterone. Its total endometrial transformation dosage per 10 to 14 days in women is 200 to 700 mg. Ethisterone has about 20-fold lower potency as a progestogen relative to norethisterone. It is said to have minimal antigonadotropic effect and to not suppress ovulation, which has precluded its use in hormonal contraception.