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What Is Emergency Contraception?

Emergency contraception is a way to prevent pregnancy after unprotected sex. Often called the morning-after pill, emergency contraceptive pills (ECPs) are pills that can be taken up to 120 hours (5 days) after having unprotected sex. Some types of emergency contraception work best when taken within 72 hours (3 days) after intercourse.

The copper IUD can sometimes be used as a form of emergency contraception.

How Does Emergency Contraception Work?

Emergency contraceptive pills work by delaying ovulation (the release of an egg during the monthly cycle). If fertilization and implantation have already happened, ECPs will not interrupt the pregnancy.

How Well Does Emergency Contraception Work to Prevent Pregnancy?

About 1 or 2 in every 100 women who use ECPs will become pregnant despite taking the pills within 72 hours after having unprotected sex.

The "morning-after" name is somewhat misleading: You don't have to wait until the next morning to take ECPs. Emergency contraception is most effective when taken as soon as possible after unprotected sex.

Emergency contraception will not prevent pregnancy if unprotected sex happens after taking the ECPs.

Emergency contraception does not prevent all pregnancies. So see a doctor if you don't get your next expected period after taking ECPs.

Does Emergency Contraception Help Prevent STDs?

No. Emergency contraception does not protect against STDs. Couples having sex must always use condoms to protect against STDs even when using another birth control method.

Are There Any Side Effects With Emergency Contraception?

ECPs can cause some minor side effects for a few days, including:

  • nausea
  • vomiting
  • breast tenderness
  • headaches
  • spotting

These usually are minor, and most improve within 1 to 2 days. A girl's menstrual period may be temporarily irregular after she takes ECPs.

Who Can Use Emergency Contraception?

Emergency contraception is an option for a couple if:

ECPs are also available to young women who are forced to have unprotected sex.

Emergency contraception is not recommended:

  • for females who know they are pregnant
  • as a regular birth control method (it's designed for emergencies)

Where Is Emergency Contraception Available?

Some types of emergency contraceptive pills are available over the counter at drugstores and pharmacies for anyone of any age without a prescription.

One type of emergency contraception (which works well up to 5 days after unprotected sex) is only available by prescription.

A copper IUD used for emergency contraception needs to be placed by a doctor or . This can be done at a doctor's office or a health clinic, like Planned Parenthood.

How Much Does Emergency Contraception Cost?

Depending on the type of pills prescribed, ECPs cost between $15–$70. Many health insurance plans cover the cost of emergency contraception and family planning clinics (such as Planned Parenthood) charge much less.

When Should I Call the Doctor?

Someone who uses emergency contraception should call the doctor if they:

  • might be pregnant
  • have a change in the smell or color of her vaginal discharge
  • have unexplained fever or chills
  • have belly or pelvic pain
  • have pain during sex
  • have heavy or long-lasting vaginal bleeding
  • miss their period within 4 weeks of using emergency contraception
Medically reviewed by: Lonna P. Gordon, MD
Date reviewed: January 2022