Emergency contraceptives (EC) are defined as drugs or devices used to prevent pregnancy after unprotected sexual intercourse. This is achieved through the administration of hormones (either a progestin only, or a combination of estrogen and progestin) commonly found in routine oral contraceptives.

Much like its daily-use counterparts, Levonorgestrel tablets, 0.75mg work to prevent unwanted pregnancy by preventing or delaying ovulation. Once pregnancy begins, the hormones in Levonorgestrel tablets, 0.75mg will no longer interfere with the pregnancy. Levonorgestrel tablets, 0.75mg should not be confused with mifepristone (also known as Mifeprex®, the "abortion pill," or RU-486).

When considering emergency contraception, careful consideration should be paid to the name of this form of birth control – it is designed for emergency use, and should not be used as a primary form of contraception. At its most effective (taken within 24 hours of intercourse), Levonorgestrel tablets, 0.75mg are 89-95% effective. Proper use of a male condom is 97% effective, IUD's are between 98.5-99.9% effective, and most common female oral contraceptives range between 99.5-99.9% effective. It is important to resume or continue normal contraceptive methods immediately after use of emergency contraceptives.

It is also important to note that emergency contraceptives may prevent pregnancy but do NOT protect against sexually transmitted diseases, including HIV, the virus that causes AIDS.