The hormones are estrogen and progestin, which are in regular birth control pills. However, emergency contraception provides a short, strong burst of hormones that temporarily interfere with the hormone patterns essential for pregnancy to continue. Treatment is most effective if initiated within the first 12-24 hours after unprotected intercourse, but can work as long as treatment is begun within 72 hours. Analysis of many studies of the morning-after pill indicates that it reduces the risk of pregnancy by approximately 75 percent. Nausea and vomiting is a common side effect of the morning-after pill.
Some women also experience breast tenderness, abdominal pain, headache or dizziness with treatment.
These symptoms all subside within a day or two after treatment is completed. There could also be some disruption of a woman's next menstrual cycle. Before taking emergency contraception , it is important to discuss it thoroughly with your provider to see if it's the right choice for you. Analysis of many studies of the morning-after pill indicates that it reduces the risk of pregnancy by approximately 90 percent if taken within 72 hours. Click on her picture for her bio.