STD Home > Important Instructions for Ulipristal
What Should I Do If I Miss a Dose?Ulipristal should only be used for a single episode of unprotected sex or birth control failure. Contact your healthcare provider immediately if you vomit within three hours of taking your dose. He or she may prescribe another dose for you.
How Does This Emergency Contraceptive Work?Ulipristal works by blocking the effects of progesterone and works primarily by inhibiting or delaying ovulation (the maturation and release of eggs from the ovaries). It is also thought that ulipristal may alter the lining of the uterus (endometrium), which could prevent a fertilized egg from implanting.
Effects of UlipristalIn one clinical study, 1.9 percent of women who took ulipristal within 72 hours of unprotected sex became pregnant, compared to the predicted pregnancy rate of 5.6 percent if no emergency contraception is used.
- Ulipristal requires a prescription from a healthcare provider.
- It comes in a package with only one tablet that is taken as a single dose.
- The sooner it is taken, the more effective it is at preventing pregnancy. Ulipristal should be taken within five days (120 hours) after unprotected sex or a birth control failure.
- Ulipristal can be taken with or without food.
- If you vomit within three hours of taking ulipristal, contact your healthcare provider right away to see if you need to take another dose.
- Ulipristal can be taken at any point in the menstrual cycle.
- For the medication to work properly, it must be taken as prescribed.