What is it?

A birth control method used within 72 hours of unprotected intercourse to prevent an unwanted pregnancy. The most commonly used option is combined oral contraceptives (birth control pills cotaining ethinyl estriadial [the estrogen component] and norgestrel or levonorgestrel as the progestin component). Other options include the use of progestin-only minipills (known as Plan B) or insertion of a copper-releasing intrauterine device (IUD) within 5 days. These methods are acquired by prescription only.

The product most prescribed by doctors is a combined oral contraceptive method called Preven. It is a kit that comes pre-packaged with a pregnancy test and the four pills to be taken.

How does it work?

When given before ovulation, the combined oral contraceptives prevent ovulation or delay it. When the treatment is taken after ovulation and if fertilization has already taken place, failure of the treatment may be more likely. The mechanism of action for emergency contraceptive pills is to prevent pregnancy, NOT to interrupt or disrupt an already established pregnancy.

The use of an IUD for this purpose acts primarily to prevent fertilization, but it is more likely that the presence of an IUD, or effects of the copper ions, may interfere with implantation.

Another effective, save and convenient emergency contraceptive method is known as Plan B. It is a progestin-only birth control pill and, therefore, has no estrogen-related side effects such as nausea and vomiting. It also may be safely used by women who are breast-feeding. Also, fewer tablets are taken: two vs. four with Preven or even 8 or more pills with the use of other oral contraceptives. The cost is probably a little higher and the kit does not contain a pregnancy test, as does Preven.