Osmosis video - Progestins and antiprogestins

Progestins are synthetic that mimic the effects of progesterone, a hormone that plays a role in the menstrual cycle and pregnancy. Common uses of progestins include hormonal contraception (either alone or with estrogen), and prevention of endometrial hyperplasia from unopposed estrogen in hormone replacement therapy. Progestins are also used to treat secondary amenorrhea, dysfunctional uterine bleeding, endometriosis, and breast cancer. On the other hand, antiprogestins are drugs that block the effects of progesterone. Antiprogestins are used in pregnancy termination and emergency contraception.