Emergency Contraceptive Pills

Emergency contraception pills contain high doses of the same hormones that are in birth control pills. The high dose of hormones is short lived. Cases of deep vein thrombosis (blood clotting) have been reported in women using the emergency method. These pills are not designed to terminate an existing pregnancy and should not be confused with Mifeprex, also referred to as RU-486, which is used to terminate (abort) an existing pregnancy. Emergency contraceptive pills are taken in 2 doses, 12 hours apart. The Preven plan consists of 2 doses of pills, each containing a combination of estrogen and progestin, taken 12 hours apart.

The first dose should be taken within the first 72 hours after unprotected intercourse. Some studies show they are effective if taken after that time (up to 120 hours), but they are most effective in the first 72 hours. According to the Reproductive Health Technologies Project, Preven reduces the chance of pregnancy by 75% when used as directed.

Plan B is a progestin-only emergency contraceptive. Plan B should be used within 72 hours of unprotected intercourse. The first dose should be taken as soon as possible after unprotected intercourse, and the second dose is taken 12 hours later. The sooner it is used, the more effective it is. According to the Reproductive Health Technologies Project, Plan B reduces the chance of pregnancy by 89% when used as directed.  

Some other kinds of birth control pills can also be used for emergency contraception. The dosage depends on the brand. Consult your health care provider to learn about options. The sooner after intercourse that emergency contraceptive pills are taken, the more effective they are.

Emergency contraception pills are currently available by prescription only. Contact your health care provider or see the contact information in For More Information if you are seeking emergency contraception. Cost depends on the health care facility, and may be provided on a sliding scale based on income. Prices for emergency contraceptive pills generally range from $8 to $50.