Progestogen-only contraceptive implant
Etonogestrel
Brand names: Nexplanon, Implanon NXT
Adult dose
Dose: 68mg subdermal implant in non-dominant upper arm; effective for 3 years
Route: Subdermal implant
Frequency: every 3 years
Clinical pearls
- Most effective LARC; failure rate <0.05%/year
- Insertion technique critical — non-palpable implant requires imaging
- Bleeding pattern may continue throughout use
Contraindications
- Active VTE
- Hormone-dependent tumour
- Severe hepatic disease
- Undiagnosed vaginal bleeding
Side effects
- Bleeding pattern changes (most common)
- Acne
- Weight change
- Headache
- Mood change
- Implant migration (rare)
Interactions
- Enzyme inducers (rifampicin, carbamazepine, phenytoin, St John's wort) — efficacy lost — use additional method
Reference: BNF; FSRH CEU guidance; NICE CKS; https://bnf.nice.org.uk/drugs/etonogestrel/. Verify against your local formulary and the latest BNF before prescribing.
Related
Curated clinical cross-links plus same-class fallbacks.
Calculators
Pathways
- Spinal Anaesthesia Hypotension Management · AAGBI; ASA
- Pre-Eclampsia / Eclampsia in ED · NICE NG133; RCOG Green-top 10A
- Suspected Ectopic Pregnancy · NICE NG126; RCOG Green-top 21
- Polycystic Ovary Syndrome (PCOS) · International PCOS Guideline 2023; NICE CKS
- Pre-eclampsia Management · NICE NG133 2019
- Ectopic Pregnancy · NICE CG154 / RCOG GTG 21