Why is levonorgestrel used in emergency contraception?

Emergency contraception is intended for use after sex without contraception or when contraception may have failed. Levonorgestrel acts mainly before ovulation by changing the timing of egg release. It does not end an established pregnancy and is not the same as an abortion medicine.

It is time-sensitive, and the sooner it is taken after the event, the better the chance it can work. It does not provide continuing protection for later sex in the same cycle, so ask a pharmacist or clinician about an ongoing contraceptive method.

Take it as soon as possible according to the product instructions or advice from a pharmacist. Tell the pharmacist about regular medicines, recent hormonal contraception, vomiting, or another episode of unprotected sex. Your next period may come earlier or later than expected, and spotting or nausea can occur.

If you vomit soon after taking the tablet, contact a pharmacist promptly because another dose may be needed. Read more about [Levonorgestrel](/materials/levonorgestrel/).

Take a pregnancy test if your period is notably late, unusually light, or pregnancy symptoms develop. Seek urgent care for severe lower abdominal pain, fainting, or heavy bleeding, particularly if pregnancy is possible. Contact a clinician if you need help choosing ongoing contraception or have concerns about an exposure to infection.

Ask whether levonorgestrel is suitable after the timing of sex, when to restart or begin regular contraception, what to do if you vomit, and when pregnancy testing is appropriate.