List of products in the National Drug Code with proprietary name . Ulipristal is used by women to prevent pregnancy after birth control failure (such as a broken condom) or unprotected sex. This medication is an emergency contraceptive and should not be used as a regular form of birth control. It works mainly by preventing the release of an egg (ovulation) during your menstrual cycle. It also makes vaginal fluid thicker to help prevent sperm from reaching an egg (fertilization) and changes the lining of the uterus (womb) to prevent attachment of a fertilized egg. Using this medication will not stop an existing pregnancy or protect you or your partner against sexually transmitted diseases (such as HIV, gonorrhea, chlamydia). This medication may not work well in women who are overweight (for example, body mass index greater than 30) or if you are using certain other medications. This effect can result in pregnancy. Talk to your doctor for more details and to see if this medication is right for you (see also Drug Interactions section).