Is emergency contraception safe?

“These are extraordinarily safe drugs,” says Dr. James Trussell, faculty associate at Princeton University and researcher in the area of reproductive health, who has actively promoted making emergency contraception more widely available. “You couldn’t kill yourself with an overdose if you tried. No deaths have been linked to using emergency contraceptive pills, and the benefits of being able to prevent pregnancy after sex outweigh any possible risks of taking the pills.” 

That said, according to the Mayo Clinic, the morning-after pill isn’t appropriate for everyone. Tell your health care provider if:

  • you’re allergic to any component of the morning-after pill
  • you’re taking certain medications that may decrease the effectiveness of the morning-after pill, such as barbiturates or St. John’s wort
  • you’re breast-feeding (Plan B One-Step and Next Choice can be used during breast-feeding, but ella is not recommended) (2)

What if you have cardiovascular problems?

Some women have been told not to use birth control pills because they are at risk of stroke, heart disease, blood clots, or other cardiovascular problems. However, estrogen and progestin—the hormones found in emergency contraceptive pills used on an emergency basis—do not carry the same risks as taking oral contraceptives every day.

If your health care provider has said you should absolutely avoid estrogen, you can probably still use one of the three other types of emergency contraception: progestin-only pills (like Plan B One-Step, Next Choice One Dose, Next Choice, or Levonorgestrel Tablets), ulipristal acetate (ella) or the Copper-T IUD.  (1)

When is emergency contraception NOT recommended?

If you’re pregnant: The only time all emergency contraception is “contraindicated”—meaning you should not use it—is when you know you are pregnant. Emergency contraceptive pills won’t work then, and using an IUD as emergency contraception could increase your risk of infection during pregnancy.

If you’re having regular sex: The most important thing to know is, except for the IUD, pills aren’t as effective as any ongoing method. The morning-after pill is perfect for women who have occasional unprotected sex, but women who have regular sex need a regular, ongoing method. An estimated one to two out of 100 women who have unprotected sex one time and correctly use the morning-after pill will become pregnant. “Our guess is that if you use Plan B or One Step, if you were to use it every time you had unprotected sex, 20% of women would get pregnant in a year,” asserts Dr. Trussell.

If you’re overweight or obese: All emergency contraceptive pills, regardless of type, appear to be significantly less effective for obese women. This is an important consideration in the United States, where more than 35% of adults are obese. (3)

In clinical trials of women using EC pills (progestin-only, such as Plan B One-Step or Next Choice, or ulipristal acetate, such as ella) obese women (with a body mass index of 30 or greater) became pregnant more than three times more often than non-obese women. However, ulipristal acetate (ella) may be more effective for overweight or obese women than progestin-only EC (Plan B One-Step, Next Choice).

The best choice for emergency contraception for overweight or obese women is the copper IUD. The effectiveness of the copper IUD used as EC is greater than 99%, no matter how much you weigh (and it provides at least 10 years of excellent ongoing contraception).

If you’re obese or significantly overweight and you can’t get an IUD or ella within five days of unprotected sex, but you can get progestin-only EC (like Plan B One-Step or Next Choice), take it as soon as possible. In the United States, you can get progestin-only EC at the pharmacy without a prescription if you’re 17 or older. (1)