Notrel is a combination of progestin hormone and estrogen hormone that is used to prevent pregnancy. It functions by stopping the release of an egg (ovulation) during a woman's menstrual cycle. It also prevents pregnancy by thickening vaginal fluid thus preventing the sperm from reach to and fertilizing the egg. It also changes the lining of the womb to prevent the fertilized egg from attaching and thus the fertilized egg will pass out of the body. Nortrel does not protect against or treat sexually transmitted diseases such as Chlamydia, HIV, and gonorrhea.