Executive summary (why this matters)
- LARC methods are user-independent and therefore more effective with typical use than pills for many patients.
- Core LARC options: Cu-IUD, LNG-IUS, etonogestrel implant, DMPA injection.
- Key counselling lever: expected bleeding patterns (irregular bleeding early on is common; many discontinue due to lack of counselling).
- High-yield choice rule: if adherence is a concern or EC is needed, consider Cu-IUD.
Quick comparison (what patients ask)
- Cu-IUD: hormone-free; lasts years; may increase bleeding/cramps; also the most effective EC when fitted promptly.
- LNG-IUS: reduces heavy bleeding/dysmenorrhoea for many; irregular spotting initially; licensed duration varies by device.
- Implant: very effective; irregular bleeding common; fertility returns quickly after removal.
- DMPA injection: 12–13 weekly; can cause weight gain and delayed return to fertility; consider bone health discussions for long-term use.
Timing pearls (postpartum, breastfeeding, and practicalities)
- Postpartum: IUD/IUS is often fitted from around 4 weeks postpartum in many pathways; implants and POP are commonly suitable earlier depending on service/local protocol.
- Breastfeeding: progestogen-only methods are generally compatible; individualise and follow local maternity/sexual health guidance.
- STI risk: LARC does not protect from STIs → discuss condoms/dual protection; screen where indicated.
When to refer / urgent assessment after IUD/IUS
Severe pelvic pain, fever, purulent discharge (PID concern), pregnancy with IUD in situ, missing threads with pain/bleeding, or suspected perforation requires urgent assessment via sexual health/gynae pathways.
Managing unscheduled bleeding (fast framework)
- First 3–6 months: expect irregular bleeding with implant/IUS; reassure if no red flags.
- Always exclude: pregnancy (test), infection (STI risk), and cervical pathology (screening status, postcoital bleeding).
- If persistent or new change after stability: assess for endometrial risk factors and consider referral.
Frequently asked questions
Which LARC is best for heavy menstrual bleeding?
The LNG-IUS is commonly used to reduce heavy menstrual bleeding and dysmenorrhoea (device and indication specifics depend on local pathway and product licence).
Which method is best when adherence is poor?
Any LARC reduces user error. If EC is needed or hormone avoidance is preferred, Cu-IUD is particularly useful.
Transparency
This page is an educational, clinician-written summary of publicly available NICE guidance intended for trained healthcare professionals. It uses original wording (not copied text) and should be used alongside the full NICE source, local pathways, and clinical judgement. Doses provided are for general reference; always check the BNF/SPC.