The copper IUD is the most effective option and should be offered first: fit within 5 days of the first unprotected sex, or within 5 days of the earliest likely ovulation. Offer an oral option as a bridge if an IUD is wanted but cannot be fitted immediately.
Oral options
- Ulipristal acetate 30 mg, up to 120 h (5 days): more effective than levonorgestrel nearer ovulation
- Levonorgestrel 1.5 mg, up to 72 h (3 g if BMI over 26 or weight over 70 kg)
- Enzyme inducers reduce efficacy: use a copper IUD, or a double-dose of levonorgestrel
- Ulipristal and progestogens interact: see timing below
Copper IUD
- Most effective (pregnancy rate well under 1%)
- Works up to 5 days after UPSI or earliest ovulation
- Provides ongoing contraception
- Requires a trained fitter
Copper IUD (most effective)
- Within 120 h of UPSI or earliest ovulation
- Over 99% effective
- Offer first line
Ulipristal acetate
- Within 120 h
- Delay hormonal contraception 5 days
- Caution in severe asthma on steroids
Levonorgestrel
- Within 72 h
- Double dose if BMI over 26 or enzyme inducers
- Less effective after ovulation
Consultation
1
1. Assess risk
Timing of each episode of unprotected sex, cycle day and likely ovulation, missed pills or method failure, and weight or BMI.
Timing of each episode of unprotected sex, cycle day and likely ovulation, missed pills or method failure, and weight or BMI.
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2
2. Choose method
Offer the copper IUD first. If oral: ulipristal is generally preferred nearer ovulation; avoid starting progestogen contraception for 5 days after ulipristal (it reduces its effect).
Offer the copper IUD first. If oral: ulipristal is generally preferred nearer ovulation; avoid starting progestogen contraception for 5 days after ulipristal (it reduces its effect).
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3
3. Quick-start and follow-up
Levonorgestrel: can quick-start hormonal contraception immediately with extra precautions. Advise a pregnancy test if the next period is late or lighter than usual.
Levonorgestrel: can quick-start hormonal contraception immediately with extra precautions. Advise a pregnancy test if the next period is late or lighter than usual.
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4
4. STI and ongoing
Offer chlamydia and gonorrhoea testing if at risk, and start reliable ongoing contraception with condoms.
Offer chlamydia and gonorrhoea testing if at risk, and start reliable ongoing contraception with condoms.
Key timing points
- Vomiting within 2 to 3 h of an oral dose: repeat it
- Ulipristal then progestogen started too soon reduces efficacy of both
- Breastfeeding: avoid breastfeeding for 1 week after ulipristal
Pitfalls
- Not offering the most effective method (copper IUD)
- Ignoring weight and enzyme inducers with levonorgestrel
- Starting a progestogen too soon after ulipristal
- Forgetting ongoing contraception and STI screening
MedPrep - www.medprep.uk - Educational revision aid only. Not clinical guidance. Doses are adult examples; check the BNF, current guidelines and local policy, and seek senior advice. Nov 2026