What it is used for
- Preventing pregnancy after unprotected sex or contraceptive failure (such as a missed pill or split condom)
How it works
It mainly works by delaying or preventing the release of an egg from the ovary. It is most effective the sooner it is taken after unprotected sex and does not end an existing pregnancy.
How it is taken
A single tablet taken as soon as possible after unprotected sex; the effective time window differs between the two main types. Available from pharmacies in many countries. Take it exactly as the pharmacist, doctor, or label directs, and seek advice if you vomit soon after taking it.
No doses here on purpose. The right strength and schedule depend on you — only a doctor or pharmacist should set them. Always follow your prescription and the label.
Common side effects
- Nausea
- Headache
- Tiredness
- Abdominal or pelvic pain
- Dizziness
- Period arriving earlier or later than expected
- Breast tenderness
Serious effects — get help
- Severe lower abdominal pain in the weeks afterwards (possible ectopic pregnancy needing urgent care)
- Signs of a serious allergic reaction
If a reaction is severe — for example trouble breathing, swelling of the face or throat, or collapse — go to the nearest emergency room now or call your local emergency number. Do not wait for an online consultation.
Interactions to watch
- Liver-enzyme-inducing medicines (some epilepsy, HIV, and TB drugs, and St John's Wort) can reduce effectiveness
- The two types should not be used together in the same cycle without advice
- Effectiveness can be affected by recent or ongoing hormonal contraception
Who should take care
- Take a pregnancy test if your next period is more than a week late or unusually light
- It is for occasional emergency use, not regular contraception
- Tell the pharmacist if you are breastfeeding, take other medicines, or weigh significantly above average, as advice may differ
- Does not protect against STIs; consider STI testing after unprotected sex