Navela is an emergency contraceptive that can be used within 72 hours (3 days) after unprotected intercourse or after failure of your usual method of contraception. Navela contains a synthetic hormone-like medicine called levonorgestrel. It prevents about 85% of expected pregnancies if used within 72 hours of unprotected intercourse. It will not prevent pregnancy in every case and is more effective if used as soon as possible after unprotected intercourse. It is better to take it within 12 hours than to wait until the third day.