How effective is emergency contraception?

Overall, emergency contraception is very effective. Emergency contraception is often called the “morning after pill,” but while within the first 24 hours is ideal, and 72 hours is an often-cited timeframe, five days is the true limit—bearing in mind that with some methods, success becomes less likely closer to five days.

The least effective method is the combined progestin/estrogen method (large doses of birth control pills, taken 12 hours apart). This will prevent roughly three-quarters of the pregnancies that would statistically otherwise occur, and its effectiveness diminishes after 24 hours.

The progestin pills—Plan B, Plan B One-Step, Next Choice—will prevent up to 95 percent of pregnancies when taken in the first 24 hours after sex, but up to 120 hours their effectiveness is reduced (though still higher than the progestin/estrogen method).

The progesterone receptor pill Ella is more effective than either of the previous options, and its effectiveness does not decrease between 72 and 120 hours, but its prescription requirement means factoring in degree of access to a physician and the drug's local availability.

IUDs are also almost completely effective up to the five-day limit, but must be implanted by a healthcare professional, which may delay treatment.

Where can I get it and what does it cost?

Prices and availability for emergency contraception vary widely, and depend on access to insurance, doctors, and pharmacies. Not all pharmacies stock the medications, so you will want to call and ask.

The over-the-counter medications will cost $10 to $70 out of pocket; somewhat less with insurance co-pays.

The prescription drug Ella is more expensive—it can be delivered overnight for about $80 with a prescription—but that is without the cost of seeing a physician. For this reason, you may want to ask for a prescription at the time of your regular gynecology exam, and keep it on hand.

An IUD is the most expensive option, costing up to several hundred dollars with the physician’s visit. Uninsured persons may want to investigate reproductive health clinics, which might have sliding fee scales. Even insured people should consult their policies: most states require any insurer covering prescription drugs to cover all FDA-approved medications and, usually, the relevant medical services. But 20 states do not require this, and two (Arkansas and North Carolina) exclude these drugs from their required coverage.