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Emergency Contraception Fact Sheet

How do I use it?

Emergency contraception can be used up to 120 hours (five days) after unprotected sex to prevent pregnancy. There are two main types of emergency contraception:

  1. Emergency contraceptive pills which are more effective the sooner you take them.
  2. The copper T IUD which can be used to prevent pregnancy up to five days after unprotected sex.

How effective is it?

While emergency contraception reduces the risk of pregnancy up to five days, it is most effective when taken within 72 hours (three days) of having unprotected sex. Taken within 72 hours, about 15 women out of 100 who use emergency contraception will become pregnant.

If put into place within five days after having sex, only about one woman out of 100 using the Copper T IUD will become pregnant.

Advantages of emergency contraception

  • Emergency contraception does not require the consent of the female's partner

  • Is safe and effective in preventing pregnancy after unprotected sex

  • Available over-the-counter for both females and males age 17 and older

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Quick Facts

Effectiveness in Preventing Pregnancy

  • Of 100 women who take emergency contraception pills within five days of unprotected sex, about 15 would expect to become pregnant
  • Emergency contraception works best the sooner it is taken and best when used within 72 hours
  • The Copper T IUD is also very effective in preventing pregnancy. If put into place within five days after having sex, only one women out of 100 using the Copper T IUD will become pregnant

STI Protection

  • No

Clinic Visit Required

  • Yes, if under age 17 or using a Copper T IUD as emergency contraception

What is emergency contraception?

Emergency contraception – sometimes called the Morning After Pill – are pills that have hormones similar to what is in regular birth control pills. Hormones are chemicals that control how different parts of your body work. Emergency contraception prevents pregnancy mainly by keeping the ovaries from releasing eggs. Emergency contraception also works by causing the cervical mucus to thicken, which blocks sperm from meeting with and fertilizing an egg.

Three brands of emergency contraception are sold in the U.S.:

  • Plan B One-Step
  • ella
  • Next Choice

You might want to use emergency contraception if you have sex without using any type of birth control; if the birth control you use failed (for example, if a condom broke or you forgot to take your birth control pills); or if you were forced to have sex.

How do I get it?

Women (and men) 17 or older can buy Plan B One-Step and Next Choice over-the-counter at a pharmacy or clinic. If you are under 17, a prescription is needed. Women of any age need a prescription for ella.

Call the pharmacy before you go to make sure they stock emergency contraception and to see what hours they are open (all emergency contraception will be behind the counter and, even if the rest of the store is open, you will not be able to get what you need if the pharmacy is closed). Make sure you have either your prescription or photo I.D. to prove your age.

Drawbacks of emergency contraception

  • Emergency contraception is not as effective as some other types of birth control
  • Works best when taken quickly (within 72 hours)
  • Requires a clinic visit and prescription if you are under age 17
  • Does not work if you are already pregnant
  • Provides no protection against sexually transmitted infections (STIs)
  • May cause side effects like nausea (anti-nausea medicine might help with this), vomiting, stomach pain, and headaches


Office on Women's Health:

Centers for Disease Control and Prevention

Food and Drug Administration