Emergency contraception - get the facts

Emergency contraception (EC) can prevent pregnancy after sex, but only if you use it as soon as possible–within a couple of days. Learn more about EC here.

Table of Contents

Five Key Facts

Don’t wait! Take EC as soon as possible after unprotected sex.
  1. Birth control methods that can help prevent pregnancy after unprotected sex are called Emergency Contraception (EC).
    • Using EC pills or getting an emergency copper IUD (intra-uterine device) inserted as soon as possible after unprotected sex can greatly lower your chances of getting pregnant.
    • Both methods of EC are effective up to 5 days (120 hours) after unprotected sex. EC pills are sometimes called “the morning after-pill,” but it’s best to take EC as soon as possible.
  2. EC is safe and effective.
    • Millions of women have safely used EC to prevent unintended pregnancies for over 30 years.
    • Some women also learn how to use daily birth control pills as EC. Learn more at www.not-2-late.com.
  3. EC pills work by keeping an egg from leaving the ovary.
    • Just like daily birth control pills, EC pills may also keep the sperm from meeting the egg. However, it cannot stop a fertilized egg from attaching to the lining of the uterus.
    • EC is not the abortion pill and will not end an existing pregnancy or cause an abortion or miscarriage.

All women have the right to access EC pills today and/or may contact (617) 616-1636 for help getting an IUD inserted within five days.

Emergency IUD insertion is the most effective EC method (99.9% effective) for all women. The IUD is a small copper and plastic device that a provider can place inside a woman’s uterus to prevent pregnancy. This method can be used for up to 10 years, or removed at any time. You can ask your provider or call today if an IUD may be right for you.

  1. There are two types of EC pills that are FDA approved for use
    • ella® (ulipristal acetate) is the most highly effective EC pill available to help prevent pregnancy for the first 5 days after unprotected sex. ella®:
      • Prevents more pregnancies than progestin-only pills, especially in women who:
        • Weigh more than 165 pounds, or
        • Have recently had or will have a period within two weeks, or
        • Were unable to get EC until 3-5 days (72-120 hours) after the unprotected sex
      • Might make hormonal birth control methods (like the pill, ring, or patch) less effective right after taking it. As with all EC, a back-up birth control method (like a condom) should be used if possible until your next period starts.
  • Plan B One-Step® and lower cost generic (progestin-only) pills reduce the risk of pregnancy by 88%. Progestin-only pills:
    • Work best to prevent pregnancy for the first 3 days after unprotected sex but may still help to reduce the risk of pregnancy on the 4th or 5th day
    • May not work as well if you weigh over 165 pounds and may not work well at all if you weigh over 175 pounds.

Research shows that progestin-only pills do not cause birth defects, and can be safely used by breastfeeding women. If you find out later that you were pregnant when you took this type of EC, it will not harm you or your pregnancy. It will not affect your ability to become pregnant in the future.

ella® ella® was FDA approved in 2010. More research is needed to learn if pregnant and breastfeeding women can safely use ella®. Before choosing ella®, you may want to take a pregnancy test to find out if you were already pregnant before the unprotected sex.
  1. After taking EC pills, some women may experience mild, short-term side effects.
    • You may have more or less bleeding than normal with your next period. Your next period may start earlier or later than normal. If your period is more than 1 week late, you may be pregnant, and should take a pregnancy test.
    • You may experience nausea, stomach pain, headache, fatigue and dizziness, similar to the side effects of daily birth control pills. If you have severe, long-lasting stomach pain after taking EC pills, call your doctor right away.
    • Your doctor can give you medication to help prevent nausea. If you vomit within 2-3 hours of taking a dose of EC pills, call your doctor to see if you need to take another dose.
    • After taking EC pills, it is highly recommended to use a back-up birth control method if possible, such as a condom, until your next period starts.

The doctor or nurse can answer any questions you may have about EC

Still need help getting low-cost EC or other confidential support services?

If you want EC right away, visit a clinic or pharmacy or search online for the pills by name.

  • ella® is available with a prescription from a doctor. You can also order ella® for next day shipment at a low cost from: www.prjktruby.com/about-2/products/ella
  • Plan B One-Step® can be sold to anyone of any age at most pharmacies. Pharmacies can also sell low-cost progestin-only pills (generics) without a prescription.

To prevent HIV and other STDs, use a condom

Latex or plastic condoms are the only kinds of birth control that are also highly effective in preventing HIV and other sexually transmitted diseases (STDs). If you use other forms of birth control but also want protection against HIV and other STDs, use a condom in addition to the birth control method you are using.

More information

For more information about how effective a method is and how to use it correctly, ask your doctor, nurse, midwife, or family planning counselor (health care provider).

To find other counseling programs and services near you, call (English, translation available):


  • (800) 235-2331
  • TTY: (617) 437-1672

Domestic Violence Hotline:

  • (877) 785-2020
  • TTY: (877) 521-2601

Rape Crisis Hotline:

  • English: (800) 841-8371
  • Spanish: (800) 223-5001
  • TTY: (617) 492-6434

Massachusetts Department of Public Health

Additional Resources



(617) 624-6062


Massachusetts Department of Public Health
250 Washington St.
5th Floor
Boston, MA 02108