Alternative Name: ZK 98.299, ZK 98 299
Description: A study in bonnet monkeys found that low-dose onapristone treatment prevented pregnancy without disturbing the menstrual cycle and ovulation in the majority of cycles. Anovulation and luteal insufficiency occured in some animals during prolonged treatment. Given the resulting inhibition of endometrial receptivity, onapristone was studied as an antiprogestin for endometrial contraception.
Updated date: July 22, 2016