RU-486 is also known as Mifepristone or the abortion bill and it is the first pill administered during a medical (as opposed to surgical) abortion. The function of RU-486 is to block the hormone progesterone, causing the uterine lining to break down and making it impossible for pregnancy to continue.
RU-486 can also function as emergency contraception if administered after intercourse and before ovulation. Unlike other forms of emergency contraception it does not work by blocking implantation but rather by preventing ovulation. Though it can be utilized as emergency contraception it is important to note that RU-486 is distinct from all other forms of EC. No emergency contraceptives, other than RU-486 are authorized for medical abortion.
RU-486 has also been tested for use as contraception, and an anti-depressant.
