ORG 33628 and ORG 31710 to control vaginal bleeding in progestin-only contraceptive regimens.

ORG 31710 and ORG 33628 were used in studies aiming to control vaginal bleeding in combination with progestagen-only contraception in primates. Preclinical evidence in monkeys with ORG 31710 has shown that a monthly supplementary administration to a progestagen-only contraceptive improves cycle control, probably as a result of a local endometrial effect (i.e.