4 Must-Know Facts About Emergency Contraception

The FDA recently gave the green light for emergency contraception (EC), specially formulated birth control pills that prevent pregnancy soon after sex, to be available over the counter to women 18 and older. "But many women don't take advantage of EC because they don't understand how it works," says Iffath Hoskins, MD, an ob-gyn at Lutheran Medical Center in Brooklyn, who helped develop Ask Me, a campaign to raise awareness of EC. Here, Dr. Hoskins and other experts answer your most common questions.

You take two tablets: the first one as soon as possible and the second 12 hours later. EC is most effective when used within 72 hours, preventing up to 89 percent of pregnancies. You can take EC more than once during your cycle, but it can get pricey; cost varies from $25 to $40, and insurance may not cover it.

"They're completely different medicines," says Anne Davis, MD, an ob-gyn at New York-Presbyterian Hospital in New York City. The abortion pill, RU-486, is a prescription drug that terminates a pregnancy in lieu of a surgical abortion. EC, also called Plan B, delays ovulation and possibly changes the way the egg and sperm move through your system, making it less likely that they'll meet and conception will take place. "If you're already pregnant, EC won't work," says Dr. Davis.

It's not dangerous to take EC, and the side effects are minimal, says Dr. Hoskins. "You may get a headache or feel nauseous, but this is rare." Also, it's possible to experience some irregular bleeding, and your next period may come early or late, but everything should be back to normal in a month or two.

You don't need a prescription, but EC won't be out in the open on the drugstore shelves, so ask your pharmacist for it (you'll need to show ID to prove that you're over 18).

Originally published in FITNESS magazine, December 2006.