Women's health
Emergency contraception
The "morning-after" pill and emergency coil — Prevents pregnancy after unprotected sex or contraceptive failure — and the sooner, the better.
Education and reference only. This is a plain-language class overview — it deliberately contains no doses. Always check the current Summary of Product Characteristics (SmPC), the BNF and your local formulary before prescribing or administering any medicine.
Quick answer
What is Emergency contraception?
Emergency contraception reduces the chance of pregnancy after unprotected sex, a split condom or missed regular contraception. It is a backup, not a routine method, and is available as tablets or as an emergency copper coil.
- How it works: The hormonal tablets work mainly by delaying or preventing the release of an egg (ovulation), so they are most effective when taken before ovulation has happened.
- In practice: In practice the single most important message is speed: all methods work better the earlier they are used after unprotected sex.
What it is
Emergency contraception reduces the chance of pregnancy after unprotected sex, a split condom or missed regular contraception. It is a backup, not a routine method, and is available as tablets or as an emergency copper coil.
How it works
The hormonal tablets work mainly by delaying or preventing the release of an egg (ovulation), so they are most effective when taken before ovulation has happened. The copper coil works differently — copper is toxic to sperm and eggs and also prevents a fertilised egg implanting — which is why it is effective even closer to ovulation and is the most reliable option.
In practice
In practice the single most important message is speed: all methods work better the earlier they are used after unprotected sex. There are three options. The copper intrauterine device (IUD) is the most effective and can be fitted within a defined window, also providing ongoing contraception. Of the tablets, ulipristal acetate and levonorgestrel each have their place — levonorgestrel is used within a shorter window, while ulipristal covers a slightly longer one, and the choice is affected by where the woman is in her cycle, her weight (levonorgestrel is less effective at higher body weight, where a higher dose or ulipristal/IUD may be preferred), and recent or planned hormonal contraception (ulipristal and progestogens can reduce each other's effect, so timing of restarting regular contraception matters). Emergency contraception does not protect against pregnancy from sex later in the same cycle, gives no protection against sexually transmitted infections, and is not an ongoing method — so it is also an opportunity to discuss reliable regular contraception.
Examples
Practical use
How to take it & use it well
- Act as soon as you can after unprotected sex - emergency contraception works better the sooner it is used, so do not wait for symptoms or your next period.
- Levonorgestrel and ulipristal acetate are single oral tablets taken as one dose; the copper coil (IUD) must be fitted by a trained clinician within the recommended window after unprotected sex.
- If you are sick within a few hours of taking the tablet, contact a pharmacist or GP, as the dose may not have been absorbed and you may need to repeat it.
- Do not take levonorgestrel and ulipristal together, and avoid restarting or starting hormonal contraception too soon after ulipristal, as they can reduce each other's effect - ask a pharmacist about timing.
- Remember this is a one-off backup, not ongoing contraception; arrange a reliable regular method afterwards and consider an STI check if there is any risk.
Common uses
- After unprotected sex or contraceptive failure
- After a missed pill or other method failure
- When ongoing contraception is also wanted (copper IUD)
Monitoring
- A pregnancy test if the next period is late or unusually light
- Suitability and timing of restarting regular contraception
- STI risk assessment where relevant
Weighing it up
Advantages & disadvantages
Advantages
- Offers a second chance to prevent pregnancy after unprotected sex or a contraceptive accident such as a missed pill or split condom.
- The copper coil is the most effective option and can also be kept in place to provide long-term ongoing contraception.
- Tablets are widely available, including free from pharmacies and sexual health clinics in much of the UK, and can be taken quickly without a procedure.
- Using emergency contraception does not affect your future fertility.
Disadvantages
- None of the tablet options is as reliable as the copper coil, and effectiveness falls the longer you wait after unprotected sex.
- Levonorgestrel may work less well at higher body weight, so a different option may be advised.
- It gives no protection against sexually transmitted infections.
- It only covers the single episode of unprotected sex and does not protect against later sex in the same cycle.
- It can cause temporary nausea, tummy upset or changes to the timing of your next period.
Key safety principles
What to watch for
- Use as soon as possible — effectiveness falls the longer you wait.
- Levonorgestrel is less effective at higher body weight (ulipristal or the copper IUD may be preferred); the IUD is the most effective option.
- Ulipristal and progestogen contraception can reduce each other's effect — timing of restarting regular contraception matters; no protection against STIs.
Key interactions
What to avoid or check alongside
- Enzyme-inducing medicines (some epilepsy drugs, rifampicin, and the herbal remedy St John's wort) can make hormonal tablets less effective - the copper coil may be preferred in this situation.
- Ulipristal and progestogen-based contraception or levonorgestrel can reduce each other's effectiveness, so they should not be combined and timing matters.
- Medicines that raise stomach pH, such as antacids and acid-reducing drugs, may lower how well ulipristal is absorbed.
- Severe vomiting or diarrhoea soon after a tablet can stop it working, meaning a repeat dose or the coil may be needed.
Patient & carer advice
- Take it (or have the coil fitted) as soon as you can — sooner works better
- If you are sick within a few hours of the tablet, you may need another dose — ask us
- This is a one-off backup, not ongoing protection, and does not cover sex later in the cycle
Use with
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Answers
Emergency contraception: frequently asked questions
How soon should I take emergency contraception?
As soon as possible - all methods work better the sooner they are used after unprotected sex, though each has a maximum time window. Speak to a pharmacist or sexual health clinic the same day if you can.
Will emergency contraception protect me for the rest of the month?
No. A tablet only covers the single episode of unprotected sex you have already had. If you have sex again you may need protection again or an ongoing method.
Does emergency contraception cause an abortion?
No. It works mainly by delaying or preventing the release of an egg, or by stopping fertilisation. It will not end an established pregnancy.
Can I use it more than once?
It can be used more than once if needed and is safe, but it is less reliable than regular contraception and may upset your cycle. It is best kept as a backup rather than a routine method.
Why might a pharmacist recommend the copper coil instead of a tablet?
The copper coil is the most effective emergency option, works regardless of body weight, and is unaffected by enzyme-inducing medicines. It can also stay in to provide ongoing contraception.
Authoritative sources
Always verify against the source
This overview is for orientation. For doses, interactions, contra-indications and the full monograph, use:
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