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Emergency Contraception

How effective is it?

Emergency Contraceptive Pills

Progestin only:

  • Levonorgestrel (Plan B One-Step, Next Choice One Dose, and My Way): 7 out of 8 women who would have gotten pregnant will not become pregnant after taking these pills.
  • Ulipristal acetate (ella): 6 or 7 out of every 100 women who would have gotten pregnant will not become pregnant after taking ulipristal acetate.

Combined regimen:

  • Estrogen and progestin: 3 out of 4 women who would have gotten pregnant will not become pregnant after taking this combined regimen of pills.

IUD

  • The copper T IUD is the most effect emergency contraceptive method. Out of one thousand (1,000) women who use this method, only one will get pregnant.

Advantages of emergency contraception

  • Is safe and effective in preventing pregnancy after unprotected sex if used within identified window of time
  • Some are available over the counter
  • Does not require the consent of the female's partner

How do I get it?

Emergency contraception is birth control that you use after you have had unprotected sex—if you did not use birth control or your birth control failed. Most should be used within 72 hours, but research has shown it can be used up to 120 hours (5 days) after unprotected sex to prevent pregnancy. There are two main types of emergency contraception:

  1. Emergency contraceptive pills (ECPs): Depending on the type of ECPs, you can use them within 3 days or within 5 days after unprotected sex to prevent pregnancy.
  2. The copper T IUD can be used to prevent pregnancy up to 5 days after unprotected sex.

Download Emergency Contraception Fact Sheet

Quick Facts

 

Effectiveness in Preventing Pregnancy

Emergency Contraceptive Pills

Progestin only

  • Levonorgestrel (Plan B Once-Step, Next Choice One Dose, and My Way): 7 out of 8 women who would have gotten pregnant will not become pregnant after taking these pills.
  • Ulipristal acetate (ella): 6 or 7 out of every 100 women who would have gotten pregnant will not become pregnant after taking ulipristal acetate.

Combined regimen:

  • Estrogen and progestin: 3 out of 4 women who would have gotten pregnant will not become pregnant after taking this combined regimen of pills.

IUD

  • The copper T IUD is the most effect emergency contraceptive method. Out of one thousand (1,000) women who use this method, only one will get pregnant.

STI Protection

  • No

Clinic Visit Required

  • Many emergency contraceptive pills are available on drugstore shelves (over the counter). A clinic visit is required to obtain a prescription for ulipristal acetate (ella) or if seeking a Copper T IUD as emergency contraception

What is emergency contraception?

Emergency contraception is birth control that you use after you have had unprotected sex—if you didn’t use birth control or your regular birth control failed. Emergency contraception should be taken as soon as possible within 3 days or within 5 days after unprotected sex to prevent pregnancy.  All emergency contraceptive pills are more effective the sooner you take them.

There are two types of emergency contraception (EC):

1. Emergency contraceptive pills (ECPs)

Research has shown that the pills in a and b above are equally effective when taken on the first-fourth days after unprotected sex and are ineffective thereafter. Ulipristal acetate is equally effective when taken on the first-fifth days.

  • Levonorgestrel (Plan B One-Step, Next Choice One Dose, and My Way) consist of one pill that the instructions state must be taken with 3 days (72 hours).
  • Ulipristal acetate (ella) consists of one pill that must be taken within 5 days (120 hours).
  • The combined regimen consists of 2 doses of estrogen and progestin pills. The first combined dose must be taken within 3 days (72 hours) and a second combined dose must be taken 12 hours later. 

2. Emergency insertion of a copper T intrauterine device (IUD) within 5 days (120 hours)


How do I get emergency contraception?

ECPs are available at some pharmacies. Women and men of all ages can get emergency contraceptive pills other than ulipristal acetate without a prescription. You may want to check that your local pharmacy carries ECPs before making a trip there.

Women of all ages need a prescription for ulipristal acetate (ella). Contact your health care provider to get a prescription.

Many family planning clinics dispense emergency contraceptive pills and offer IUDs as a birth control option. To search for a clinic near you use our Clinic Locator.


Drawbacks of emergency contraception

  • Not as effective as some other types of birth control
  • Require a clinic visit and a prescription in some cases
  • Do not work if you are already pregnant
  • May cause side effects like nausea (anti-nausea medication might help with this), vomiting, stomach pain, and headaches
  • Do not protect against sexually transmitted infections (STIs)

Sources

Centers for Disease Control and Prevention

U. S. Food and Drug Administration

Office on Women's Health

The Emergency Contraception Website

"Contraceptive Technology," Robert A. Hatcher, MD, MPH et. al., 20th revised edition, Contraceptive Technology Communications Inc., 2011.

"The efficacy of intrauterine devices for emergency contraception: a systematic review of 35 years of experience," Cleland K, Zhu H, Goldstuck N, Cheng L, Trussell J., Hum Reprod. 2012 Jul 27(7):1994-2000.

Content created by Office of Population Affairs
Content last reviewed on February 9, 2017