Skip Navigation

Display Mode:

  • Choose Default Style
  • Choose High Contrast
California Teen Health | Teen Health Information
  • Teen Home
  • About Us
  • PAMF Home
  • Teen FAQ
  • General Health
  • Tobacco, Drugs & Alcohol
  • Emotions & Life
  • Sexual Health & Experience
Section TitleSexual Health & Experience
  • Birth Control
    • Abstinence
    • The Pill
    • Cervical Cap
    • Condom
    • Female Condom
    • Depoprovera
    • Diaphragm
    • Implanon
    • Intrauterine Device (IUD)
    • Male Contraceptive
    • Minipill
    • Morning After Pill
    • The Patch
    • The Ring
    • Seasonale
    • Spermicide
    • Sponge
    • Sterilization
    • Withdrawal
    Main content

    Birth Control

    Emergency Contraception
    (Morning After Pill)

    For people at least 17 years old, emergency contraception can be purchased over-the-counter, without a prescription.

    What is emergency contraception?

    Emergency contraception is a method of preventing pregnancy after unprotected sexual intercourse. It is for emergency use and should not be relied upon as a method of birth control. Emergency contraception is most effective if it is used as soon as possible after unprotected sex.

    How does it work?

    You take fairly high doses of progestin (a synthetic form of the hormone progesterone), with or without the hormone estrogen. (These are also the hormones used in birth control pills). If taken within 72 hours (three days) of unprotected sex, the hormones have a very high success rate at preventing ovulation or implantation of a fertilized egg in the lining of the uterus. However, even if taken less than 24 hours after unprotected sex, the highest success rate is 89 percent.

    How is it used?

    There are two effective ways to use emergency contraception. In the first method, a woman takes two prescribed progestin tablets alone. In the second, she takes hormone pills (either progestin alone or a progestin-estrogen combination) once, and then again 12 hours later. A medical provider will tell you which is correct for you.

    When should I use it?

    Emergency contraception is no substitute for good before-the-fact birth control. Talk with your health care provider about preventing pregnancy and sexually transmitted infections, before the issues arise. You would use this method only in an emergency, such as:

    • You were forced to have sex without protection.

    • You had sex without using any kind of birth control protection and do not desire pregnancy.

    • You used a condom or other barrier method but it broke.

    • You missed more than two birth control pills and didn't use a condom.
    Are there any side effects?

    Common side effects include nausea and occasionally vomiting (an anti-nausea drug is sometimes prescribed for this). If pregnancy does occur despite using the birth control pills, there is no increased risk of birth defects. You should not use emergency contraception if you are already pregnant, know you are sensitive or allergic to the medication, or have been having abnormal vaginal bleeding.

    Does it protect against sexually transmitted infections (STIs)?
    No.

    Things you should know:

    Don't just take whatever birth control pills you might have around the house or get from friends. The proper number of pills to take depends on which type of pill you use. You should check with a medical provider to find out what number of pills is right for you.

    This method is not approved for use when taken more than three days after unprotected sex. Call your health care provider to discuss your options after this three-day interval has passed.

    In some states (Alaska, California, Hawaii, New Mexico and Washington), emergency contraception can be distributed by pharmacists, without a prescription from a medical provider.

    Emergency contraception does not cause an abortion. Emergency contraception works by preventing a pregnancy from occurring, not by terminating a pregnancy. Often you will have bleeding after taking the medication, as with a period.

    Back to top
    Teen couple
    The image presented here is simply for educational purposes and represent a "typical" style of this type of contraception. PAMF does not endorse any particular brand or method of contraception.

    Additional Outside Sources
    Below are sources PAMF accessed when researching this topic. PAMF does not sponsor or endorse any of these sites, nor does PAMF guarantee the accuracy of the information contained on them.

    Planned Parenthood. Birth Control.

    womenshealth.gov Birth Control Fact Sheets [Online].
    • For Parents
    • Privacy Policy
    • Site Map
    • Website Feedback

    © 2013 Palo Alto Medical Foundation. All rights reserved. Sutter Health is a registered trademark of Sutter Health®, Reg. U.S. Patent. & Trademark office.
    Serving communities around Palo Alto, Mountain View, Fremont, San Jose, San Francisco, Oakland, Dublin, San Mateo & Santa Cruz.