Progestin-only Emergency Contraceptive Pills ("Morning After Pills")
Progestin-only emergency contraceptive pills ("morning after pills") are pills that contain levonorgestrel, a type of the hormone progestin researchers have found prevents pregnancy when taken in the few days after sex. In the United States, there are currently three progestin-only emergency contraceptive pills on the market: Plan B One-Step, Plan B and Next Choice.
Plan B One-Step contains 1.5 mg of levonorgestrel in just one pill, which you take as soon as possible after sex. The packages for Plan B and Next Choice contain two emergency contraceptive pills (each containing 0.75mg of levonorgestrel), and the instructions tell you to take them 12 hours apart. Recent studies show that you can take both pills (the full 1.5mg dose) at the same time, and one-pill emergency contraceptives are already available in a number of other countries. Research also shows that you can use emergency contraception up to 120 hours after sex, even though the instructions say to take the pills within 72 hours. About one woman in four (23%) feels sick to her stomach and about one in 17 (6%) throws up after taking progestin-only emergency contraception. (For more details about using these pills, click here.)
There are different age restrictions for the emergency contraceptive pills available in the United States, so it can be a bit confusing for consumers. If you are 17 years old and need emergency contraception, be sure to call the pharmacy first to see if they carry a brand of EC that you can buy without a prescription.
- Plan B One-Step and Next Choice are approved for sale without prescription to women and men 17 and older. Women aged 16 and younger need a prescription.
- Plan B (the original version, which contains 2 pills instead of one) is still carried in some pharmacies but will be phased out soon. To buy this pill without prescription, you must be aged 18 or older.
Plan B and other progestin-only emergency contraceptive pills reduce your risk of pregnancy by about 89%. Don't worry, that doesn't mean 11 percent of women get pregnant using these morning after pills. It just means that this type of emergency contraception prevents 89% of the pregnancies researchers would expect would happen when a woman doesn't use birth control, her contraception fails (like the condom breaks or falls off), or she is forced to have sex. Usually, if 100 women have sex without using birth control one time during the second or third week of their menstrual cycle, about 8 of them will get pregnant. But if those same 100 women also use progestin-only emergency contraceptive pills, only one will get pregnant. And emergency contraception works better the sooner you take it after sex.
To learn which brands of emergency contraception and daily birth control pills can be found in the United States or any other country, try using our up-to-date database. In addition to progestin-only emergency contraception, you can also use certain brands of birth control pills that contain two hormones (both progestin and estrogen) or the Copper-T IUD to prevent pregnancy after sex.
For a more detailed academic review of the medical and social science
literature about emergency contraception, click
here 
.