The full reasoning pathway — offer the Cu-IUD first (most effective), establish the timing window and ovulation risk, then choose oral EC by time-since-UPSI, weight and drug interactions, quick-start ongoing contraception, and safety-net.StartDecisionInvestigateActionReferStop / Admit
PresentationRequest for emergency contraception
Confirm EC is needed & reasonably exclude existing pregnancy. Timing & number of UPSI episodes since LMP, cycle length, current method, weight/BMI, enzyme inducers, breastfeeding. Risk-assess safeguarding & STI.
Step 1 · Safety — time window & pregnancyWithin 5 days of UPSI or earliest likely ovulation?
Cu-IUD: insert ≤120hr after first UPSI in the cycle, or ≤5 days after earliest estimated ovulation — whichever is later. Oral EC: LNG ≤72–96hr, UPA ≤120hr.
Cu-IUD suitable & accepted
1st line — most effective EC (>99%)
Banded copper IUD (≥380mm²) — efficacy independent of weight, ovulation timing & enzyme inducers, and provides ongoing contraception. Always co-prescribe oral EC at referral in case the coil can't be fitted or she changes her mind.
Declined / unsuitable / >5 days
Choose oral EC
Decide by time since UPSI, weight/BMI, recent progestogen & enzyme inducers.
Step 7 · oral EC choice
UPA-EC — preferred ≤120hr
ellaOne (ulipristal 30mg)
Single dose ≤120hr. More effective than LNG, especially 72–120hr & near ovulation. Do NOT start hormonal contraception for 5 days after. Avoid if progestogen taken in last 7 days, severe asthma on oral steroids, or breastfeeding (express & discard 1 week). Not recommended with enzyme inducers.
LNG-EC — ≤72(–96)hr
Levonelle (levonorgestrel 1.5mg)
Single dose ≤72hr (off-label to 96hr). Double to 3mg if >70kg / BMI >26 or on an enzyme inducer (≤28d of stopping). Can quick-start ongoing method immediately. Safe in breastfeeding. Repeat dose if vomiting <3hr.
After every oral EC
Quick-start + safety-net
Start/restart ongoing contraception (now after LNG; after 5 days for UPA), condoms until effective. Pregnancy test in 3 weeks. Offer STI screen + safeguarding review.
Step 6 · ReferEscalation
Sexual health / EC-IUD clinic for coil fitting if untrained, UPSI >120hr (over-time options), enzyme inducers needing reliable EC, or safeguarding concerns. Offer oral EC meanwhile.
Step 8 · ongoing contraception & counselling
Step 8 · Ongoing contraception & counsellingTurn EC into a plan
Quick-start an effective ongoing method (immediately after LNG; after 5 days for UPA-EC), with condoms until established. Discuss LARC as the most reliable option. Offer STI screening, address safeguarding/consent, and counsel on correct use of the chosen method to prevent repeat EC need.
Step 9 · follow-up & safety-net
Step 9 · Follow-up & safety-netConfirm it worked
Pregnancy test in 3 weeks (or if the next period is >7 days late, lighter or unusual) — EC failure can still occur. Repeat-dose if vomiting within 3 hours of an oral EC. Same-day for pelvic pain/abnormal bleeding (exclude ectopic) and seek care if pregnancy is confirmed to discuss options.
⚠️ Weight & drug-interaction rule: a 1.5mg dose of levonorgestrel should NOT be used if >70kg / BMI >26 — give the 3mg double dose, or preferably a Cu-IUD / ellaOne. Enzyme inducers reduce both oral ECs → Cu-IUD is the reliable choice.
1
Safety
Red Flags & Safeguarding — assess before prescribing
EC is time-critical but still needs a safety screen. Exclude an already-established pregnancy, recognise where EC may be ineffective, and risk-assess every request.
Pregnancy already possible EC does not work — and is not indicated — if implantation has occurred. Reasonably exclude pregnancy; if UPSI >21 days ago or amenorrhoea, do a urine βhCG → if positive, EC is inappropriate, arrange pregnancy options counselling.
UPSI >120 hours ago Cu-IUD and oral EC windows exceeded → EC likely ineffective. Refer to sexual health for assessment, discuss timing, arrange 3-week pregnancy test and ongoing contraception.
Post-ovulation UPSI Oral EC works by delaying ovulation — it is ineffective once ovulation has occurred. If UPSI is clearly luteal phase, the Cu-IUD is the only reliable option.
Safeguarding / Fraser Under 16 → assess & document Fraser competence. Under 13 → unable to consent, mandatory safeguarding referral. Screen for coercion, exploitation (CSE), trafficking and partner age gap in every request.
Ectopic risk Previous ectopic, tubal surgery, PID or IUD in situ → higher ectopic risk. EC does not cause ectopics but a failed EC pregnancy may be ectopic → safety-net for pelvic pain / abnormal bleeding.
Severe asthma on oral steroids Ulipristal (ellaOne) is contraindicated → use levonorgestrel or Cu-IUD instead.
Enzyme-inducing drugs Rifampicin, carbamazepine, phenytoin, some antiretrovirals, St John's Wort — reduce both oral ECs (incl. ≤28 days after stopping) → Cu-IUD strongly preferred; if declined, double-dose (3mg) LNG off-label. UPA not recommended.
STI risk EC contact is an opportunity — risk-assess and offer chlamydia/gonorrhoea screen and signpost to sexual health, especially <25 or new partner.
Oral EC (both LNG and UPA) works principally by delaying or inhibiting ovulation — neither is abortifacient and neither disrupts an established pregnancy, so a positive pregnancy test changes the management entirely. The copper IUD is the only EC method that works after ovulation (it is toxic to sperm and ova and prevents implantation), which is why FSRH recommends offering it to every woman seeking EC. Safeguarding screening at the point of EC is a CQC and RCGP expectation — EC requests in under-16s are a recognised marker of possible exploitation.
2
Diagnose
Is EC needed? — risk assessment & timing
Establish whether conception risk is real and pin down the timing — this drives both whether and which EC.
Reason
UPSI with no method, condom failure/slippage, missed COC/POP pills, late Depo, expelled IUD, UPSI within 5 days of a missed pill week, sexual assault (→ SARC pathway).
Timing of UPSI
Hours since the first UPSI in this cycle — and the time of every episode. Determines the LNG (≤72–96hr) vs UPA (≤120hr) vs Cu-IUD (≤120hr) window.
LMP & cycle
Last menstrual period & usual cycle length → estimate earliest likely ovulation. Cu-IUD can go in up to 5 days after earliest ovulation even if >5 days since UPSI.
High-risk window
UPSI ≤5 days before to 1–2 days after ovulation = highest conception risk — this is where UPA's efficacy advantage matters most.
Current contraception
On a hormonal method? Recent progestogen (last 7 days) reduces UPA efficacy → favour LNG. Note which method to quick-start afterwards.
Weight / BMI
Record weight — >70kg or BMI >26 changes the LNG dose (see Step 4). Does not affect UPA or Cu-IUD efficacy.
Pregnancy test
Urine βhCG if any chance of pre-existing pregnancy (e.g. earlier unprotected sex this cycle). A negative test soon after recent UPSI does not exclude that conception — document reasoning.
FSRH stresses that more than one episode of UPSI may have occurred in a cycle — you must ask about each, because oral EC taken now does nothing for an earlier high-risk exposure, and a Cu-IUD may still be offerable based on the ovulation-timing rule even when oral EC windows have closed. Quick-starting ongoing contraception at the same visit is the single biggest opportunity to prevent the next unintended pregnancy.
3
Diagnose
Method decision — offer the Cu-IUD first to everyone
FSRH: the copper IUD is the most effective EC and should be offered to all women seeking EC, then oral EC chosen if the coil is declined or unsuitable.
1st line — most effective
Copper IUD (Cu-IUD) >99%
Banded ≥380mm² device (e.g. T-Safe Cu380A). Insert ≤120hr after first UPSI or ≤5 days after earliest ovulation. Efficacy unaffected by weight, timing or enzyme inducers. Becomes ongoing contraception (5–10yr). Always offer oral EC at referral as backup.
If Cu-IUD declined / unsuitable
Ulipristal acetate (UPA)
ellaOne 30mg, single dose ≤120hr. Most effective oral option, especially 72–120hr & near ovulation. See Step 4 for the interaction/asthma/breastfeeding caveats.
Alternative oral option
Levonorgestrel (LNG)
Levonelle 1.5mg (or generic), single dose ≤72hr (off-label to 96hr). Preferred if quick-starting hormonal contraception today, breastfeeding, or recent progestogen use. Double dose if >70kg/BMI>26.
Tilts toward Cu-IUD
Wants the most effective method or ongoing LARC; post-ovulation UPSI; >72–120hr; enzyme inducers; high BMI; multiple UPSI episodes across the cycle.
Tilts toward oral EC
Coil declined or can't be fitted in time; needle/procedure aversion; current STI risk untreated; simply prefers a tablet — honour preference after informed discussion.
The Cu-IUD failure rate as EC is under 1 in 1000, versus oral EC where failure rises steeply the closer UPSI is to ovulation. Because oral EC only delays ovulation, women remain fertile later in the same cycle — the Cu-IUD removes that residual risk and carries the pregnancy-prevention forward. FSRH Algorithm 1 (Cu-IUD vs oral EC) and Algorithm 2 (LNG vs UPA) formalise this decision; offering the coil to everyone, even if most decline, is the standard.
4
Diagnose
Choosing oral EC — UPA vs LNG by timing, weight & interactions
≤72 hours
Either ellaOne (UPA 30mg)orLevonelle (LNG 1.5mg). UPA is more effective overall, especially if UPSI is close to ovulation — use FSRH Algorithm 2 / CKS to decide.
72–120 hours
ellaOne (UPA) is the oral choice. LNG is unlicensed beyond 72hr (off-label to 96hr only if other methods declined) and ineffective after 96hr.
Weight / BMI
LNG 1.5mg should NOT be used if >70kg or BMI >26 → give double dose 3mg LNG (off-label) or, preferably, UPA / Cu-IUD. UPA efficacy is less weight-dependent but may also reduce at higher weight — Cu-IUD best if high BMI.
Enzyme inducers
Both oral ECs reduced (incl. ≤28 days after stopping). Cu-IUD strongly preferred. If declined → double-dose 3mg LNG (off-label). UPA not recommended.
Recent progestogen
If progestogen (POP, HRT, etc.) taken in the last 7 days, UPA efficacy may be reduced → consider LNG instead.
Recent EC
Don't give UPA if LNG used in the preceding 7 days; don't give LNG if UPA used in the last 5 days (each can blunt the other).
Severe asthma
UPA contraindicated if severe asthma controlled by oral glucocorticoids → use LNG or Cu-IUD.
Breastfeeding
LNG safe — continue feeding. UPA → express and discard milk for 1 week. Favour LNG or Cu-IUD if breastfeeding.
UPA (a selective progesterone receptor modulator) delays ovulation even after the LH surge has begun, giving it an efficacy edge in the immediate pre-ovulatory window where LNG starts to fail. The 70kg/BMI 26 LNG threshold comes from pooled trial data showing markedly reduced efficacy at higher body weight — FSRH's off-label double-dose recommendation is the pragmatic response when a Cu-IUD or UPA isn't taken. The mutual 5–7 day exclusion between LNG and UPA exists because each is a progesterone-pathway drug that can antagonise the other's mechanism.
5
Treat
Prescribing — doses, brands & what to warn about
Most effective
Copper IUD
Banded ≥380mm² (T-Safe Cu380A). Fit ≤120hr / ≤5 days post-ovulation. Doxycycline not routine — test & treat STI risk. Warn: cramping & spotting after fitting; check threads in 3–6 weeks. Co-prescribe oral EC as backup.
Preferred oral, ≤120hr
Ulipristal acetate
ellaOne 30mg — one tablet stat. No hormonal contraception for 5 days after. Repeat if vomiting <3hr. Avoid: severe asthma on steroids; breastfeeding (express+discard 1 wk); enzyme inducers.
Oral, ≤72(–96)hr
Levonorgestrel
Levonelle 1.5mg (or Levonelle 1500 / generic) stat. 3mg double dose if >70kg / BMI >26 or enzyme inducer. Repeat if vomiting <3hr. Can quick-start a method immediately. Safe in breastfeeding.
Routes of supply
FP10 prescription, sexual health clinic, or community pharmacy (PGD / OTC purchase). Check PGD inclusion criteria if pharmacy-supplied. EC is free at sexual health & many pharmacies.
Vomiting
If vomiting within 3 hours of either oral EC → repeat the dose as soon as possible (consider an antiemetic).
Side effects
Usually mild & short — nausea, headache, fatigue, breast tenderness, lower abdominal pain. Next period may be early or late (up to ~7 days either way); spotting can occur.
If period >7 days late
Or lighter/shorter than usual, or any pregnancy symptoms → do a pregnancy test (see Step 9).
A repeat dose after early vomiting matters because absorption drives efficacy in a single-dose drug — there is no second scheduled dose to fall back on. The 5-day post-UPA contraception delay exists because progestogen started too soon binds the same receptors UPA needs, blunting its anti-ovulatory effect; conversely LNG does not have this interaction, which is why it is preferred when you want to quick-start contraception the same day.
6
Treat
Quick-starting ongoing contraception after EC
EC only covers this episode — ovulation may still occur later in the cycle. Start a reliable ongoing method now (bridging), with extra precautions until it's effective.
After LNG-EC
Quick-start the chosen method immediately. Extra precautions (condoms/abstinence): CHC & implant 7 days, POP 2 days, Cu-IUD 0 days. Pregnancy test in 3 weeks.
After UPA-EC
Wait 5 days before starting CHC / POP / implant / DMPA (UPA efficacy is reduced if progestogen started sooner). Use condoms/abstinence in the meantime, then the method's own extra-precaution window. Cu-IUD can be inserted straight away.
Bridging method
If the woman's preferred LARC can't be fitted today, bridge with a POP or CHC (started per the rules above) and book the LARC — don't leave her unprotected.
Quick-start safety
Reasonably exclude pregnancy first; quick-starting is still recommended even if pregnancy can't be fully excluded, because the benefit outweighs the small theoretical risk — just arrange the 3-week test.
Most effective next step
Use the EC visit to discuss LARC (implant/IUS/IUD) — the most effective ongoing options and the best way to prevent repeat EC visits.
The 5-day delay after UPA is the single most-missed step in EC care — starting the pill the next day (the instinctive thing) actively undermines the UPA you just gave. After LNG there is no such interaction, so same-day quick-start is correct. Either way, a documented 3-week pregnancy test closes the loop, because no oral EC is 100% and ovulation may simply have been postponed into a still-fertile window.
7
Refer
Referral & escalation
Sexual health / EC-IUD clinic
Cu-IUD fitting if you're not trained, same-day coil access, or difficult/failed insertion. Offer oral EC at the point of referral as backup.
Specialist EC advice
Enzyme-inducing medication needing reliable EC (if Cu-IUD declined), multiple complex factors, or UPSI >120hr where over-time options are being considered.
SARC / safeguarding
Disclosed sexual assault → Sexual Assault Referral Centre (forensics, prophylaxis, support). Under-13, exploitation or coercion concerns → safeguarding referral, same day.
Early pregnancy unit
Positive test after failed EC with pain or abnormal bleeding → urgent EPU to exclude ectopic.
GP manages
Standard oral EC supply, quick-starting, 3-week follow-up, STI screening & signposting — all within primary care.
Cu-IUD fitting requires DFSRH-level training and access within the 120-hour window — if you can't fit in time, a warm referral plus backup oral EC prevents the woman falling through the gap. EC requests are a recognised safeguarding touchpoint: the consultation should always screen for exploitation, and disclosures of assault need the SARC pathway, not just a tablet.
8
Lifestyle
Counselling & what to expect
Still at risk this cycle Oral EC delays ovulation — later UPSI can still cause pregnancy. Use condoms/abstinence until the ongoing method is effective.
Your next period May come early or late (up to ~7 days). If >7 days late, lighter or unusual → do a pregnancy test.
3-week pregnancy test Advise a test 3 weeks after the UPSI regardless of bleeding — confirms EC worked and that quick-started contraception is safe.
STI protection EC gives none. Offer chlamydia/gonorrhoea screening and signpost to sexual health, especially with a new partner or <25.
It's repeatable EC can be used more than once in a cycle if needed — but it's less effective than regular contraception. Frame ongoing LARC positively, without judgement.
No teratogenicity Reassure: if EC fails and pregnancy continues, neither LNG nor UPA is known to harm the fetus.
Written information Give the dose, the vomiting rule, when the ongoing method becomes effective, and clear safety-net advice in writing.
Safeguarding follow-through Document Fraser competence in under-16s and any concerns raised; arrange appropriate follow-up and support.
The commonest reason EC “fails” is not drug failure but continued unprotected sex later in the same cycle after ovulation was merely postponed — so the post-EC abstinence/condom message is as important as the tablet itself. A clear 3-week pregnancy-test instruction is the safety net that catches both true failures and any pre-existing pregnancy.
9
Safety
Follow-up & safety-netting
3 weeks
Pregnancy test after UPSI — mandatory advice. If positive → assess for ectopic and arrange options counselling / EPU as needed.
Cu-IUD users
Thread check at 3–6 weeks; confirm device in situ. Decide whether to keep it as ongoing contraception (usually yes) or remove after the next period if oral method preferred.
Ongoing method review
Check the quick-started method is tolerated & effective; address bleeding changes; reinforce missed-pill rules to avoid repeat EC.
Urgent / same-day
Positive test plus pelvic pain, shoulder-tip pain, dizziness or abnormal bleeding → exclude ectopic urgently (EPU / A&E). Severe pain or fever after Cu-IUD fitting → assess for perforation / PID.
Come back if…
Period >7 days late, lighter or unusual; ongoing concern about pregnancy; new STI symptoms; any safeguarding worry.
Any pregnancy that occurs despite EC carries a relatively higher chance of being ectopic, so a positive 3-week test with pain or abnormal bleeding is an ectopic until proven otherwise. The 3-week pregnancy test is the single safety-net that converts EC from a one-off transaction into a closed-loop episode of care.
Educational use only. Pathway based on: FSRH Emergency Contraception guideline (2017, amended 2023), FSRH Quick Starting Contraception 2017, FSRH UKMEC 2016 (updated 2019), NICE CKS Contraception — Emergency, and BLMK APC Contraception Prescribing Guidance (2024). Always check current SmPCs, FSRH decision algorithms and local formulary; adapt to individual patient context.