What is Ulipristal Acetate?

Ulipristal Acetate is a selective progesterone receptor modulator with anti-progesterone activity. Ulipristal binds to the progesterone receptor (PR), thereby inhibiting PR-mediated gene expression, and interfering with progesterone activity in the reproductive system. As a result, Ulipristal Acetate may suppress the growth of uterine leiomyomatosis. Furthermore, by inhibiting or delaying ovulation and effecting endometrial tissue, ulipristal can be used as an emergency contraception. As emergency birth control it should be used within 120 hours of sex. For fibroids it may be taken for up to six months.