Emergency Contraception

Emergency contraception is a form of birth control used to prevent pregnancy after a woman has had unprotected sex. Emergency contraception can also be used to prevent pregnancy after a sexual assault, or when any method of birth control is not used correctly. One form of emergency contraception is often referred to as the "morning after pill." It is a form of oral contraception that contains hormones, and is most effective when taken within 72 hours of unprotected sexual intercourse. In some cases, a copper intrauterine device (IUD) is used as a form of emergency contraception; it must be inserted within 5 days of having unprotected sex to be effective.

Types of Emergency Contraception

Some forms of emergency contraception are available only with a prescription, whereas others can be purchased over the counter at a pharmacy.

Over-the-Counter Oral Contraception

Available without a prescription, these forms of emergency contraception are pills that contain high levels of the hormone progestin, which works to delay ovulation. In some cases, proof of age (17 and older) is required before they can be purchased. The pills should be taken as soon as possible after unprotected sex, and are most effective within 72 hours of unprotected sex. They may be sold under the following:

  • Plan B One Step® brand name
  • Next Choice One Dose® brand name
  • My Way® brand name

In some instances in which emergency birth control is needed, women may take a higher dose of the birth control pills they are currently using, although this should only be done under the direction of a physician.

Prescription Contraception

Ulipristal acetate (sold under the Ella® brand name) is a type of emergency contraception pill. Ulipristal acetate works to delay ovulation, and may help prevent implantation. This form of emergency contraception requires a prescription. It is effective if taken within 5 days of unprotected sexual intercourse.

An IUD is a form of prescription contraception that is placed into the uterus by a physician; it can be used in emergency situations and as a regular form of birth control. An IUD may be effective if it is inserted within 5 days after having unprotected sex. The IUD works by stopping sperm from joining an egg, or preventing a fertilized egg from attaching to the uterus. The IUD may be removed after the next menstrual cycle or, if desired, can be left in place as a future method of birth control.

Risks of Emergency Contraception

Emergency contraception should not be used if a woman thinks she may already be pregnant. Side effects of oral emergency contraception include the following:

  • Nausea
  • Vomiting
  • Dizziness
  • Headaches
  • Breast tenderness
  • Abdominal pain
  • Fatigue

Side effects from an IUD are rare, but may include pelvic inflammation or injury to the uterus.

Methods of emergency contraception should not be used as a regular form of birth control.