What Are Emergency Contraceptive Pills?

• Pills that contain a progestin alone, or a progestin and an estrogen together—hormones like the natural hormones progesterone and estrogen in a woman’s body.
• Emergency contraceptive pills (ECPs) are sometimes called “morning after” pills or postcoital contraceptives.
• Work primarily by preventing or delaying the release of eggs from the ovaries (ovulation). They do not work if a woman is already pregnant (see Question 1).

• A special ECP product with the progestin levonorgestrel
• A special ECP product with estrogen and levonorgestrel
• Progestin-only pills with levonorgestrel or norgestrel
• Combined oral contraceptives with estrogen and a progestin—levonorgestrel, norgestrel, or norethindrone (also called norethisterone)

As soon as possible after unprotected sex. The sooner ECPs are taken after unprotected sex, the better they prevent pregnancy.

Can prevent pregnancy when taken any time up to 5 days after unprotected sex.

• If 100 women each had sex once during the second or third week of the menstrual cycle without using contraception, 8 would likely become pregnant.
• If all 100 women used progestin-only ECPs, one would likely become pregnant.
• If all 100 women used estrogen and progestin ECPs, 2 would likely become pregnant.

Return of fertility after taking ECPs: no delay. A woman can become pregnant immediately after taking ECPs. Taking ECPs prevents pregnancy only from acts of sex that took place in the 5 days before. They will not protect a woman from pregnancy from acts of sex after she takes ECPs—not even on the next day. To stay protected from pregnancy, women must begin to use another contraceptive method at once (see Planning Ongoing Contraception).

Protection against sexually transmitted infections (STIs): None

Some users report the following:

Changes in bleeding patterns including:

– Slight irregular bleeding for 1–2 days after taking ECPs

– Monthly bleeding that starts earlier or later than expected

In the week after taking ECPs:

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

*Women using progestin-only ECP formulations are much less likely to experience nausea and vomiting than women using estrogen and progestin ECP formulations.

Known health benefits

Help protect against:risks of pregnancy

Known health risks

None 

Emergency contraceptive pills:

• Do not cause abortion.
• Do not cause birth defects if pregnancy occurs.
• Are not dangerous to a woman’s health.
• Do not promote sexual risk-taking.
• Do not make women infertile.

Why Some Women Say They Like Emergency Contraceptive Pills

• Offer a second chance at preventing pregnancy
• Are controlled by the woman
• Reduce seeking out abortion in the case of contraceptive errors or if contraception is not used
• Can have on hand in case an emergency arises