Emergency contraception

Levonorgestrel (Emergency Contraception)

Tablet

Quick Summary

Levonorgestrel works mainly by delaying ovulation. It doesn't end an existing pregnancy.

Emergency contraception

Medical Uses

Emergency contraception: After unprotected sex or contraceptive failure.

How it's taken

Take as soon as possible after unprotected sex, ideally within 72 hours. It's not meant for regular contraception.

Your doctor decides the right dose for you and how long to take it.

Your doctor decides the right dose for you. Follow their instructions and the label.

Common Side Effects

Nausea

Sometimes.

Irregular bleeding

Changes to the next period.

Headache

Sometimes.

Interactions

Some epilepsy, TB and HIV medicines

Make it less effective; ask a pharmacist.

Critical Warnings

Not regular contraception

Talk to a doctor about regular methods.

Late or unusual period

Take a pregnancy test.

Sources and further reading

Last updated 21 October 2026. For more detail, see these trusted health organisations.