Risks

Emergency contraception is an effective option for preventing pregnancy after unprotected sex, but it isn't as effective as other methods of contraception and isn't recommended for routine use. Also, the morning-after pill can fail even with correct use, and it offers no protection against sexually transmitted infections.

The morning-after pill isn't appropriate for everyone. Don't take a morning-after pill if:

• You're allergic to any component of the morning-after pill
• You're taking certain medications that can decrease the effectiveness of the morning-after pill, such as barbiturates or St. John's wort

If you're overweight or obese, there's some indication that the morning-after pill won't be as effective in preventing pregnancy as it is for women who aren't overweight.

Also, make sure you're not pregnant before using ulipristal. The effects of ulipristal on a developing baby are unknown. If you're breast-feeding, ulipristal isn't recommended.

Side effects of the morning-after pill, which typically last only a few days, might include:

• Nausea or vomiting
• Dizziness
• Fatigue
• Headache
• Breast tenderness
• Bleeding between periods or heavier menstrual bleeding
• Lower abdominal pain or cramps