First-lineNexplanon
Etonogestrel implant
Progestogen-only subdermal implant (LARC)
3-year LARC — Pearl Index < 0.05, top-tier efficacy.
Subdermal (upper inner arm)
First-line for
- Long-acting reversible contraception
- Contraception in adolescents (Fraser competent)
Mechanism
Etonogestrel 68 mg releases ~60 μg/day → suppresses LH surge (anovulation) + mucus thickening.
"Fit and forget for 3"
- Insert day 1–5 of cycle (immediate cover)
- Any other day → 7 days barrier
- Locate before removal — palpable
Dosing
- Regimen
- 1 rod, replace every 3 years
Contraindications
- AbsoluteKnown/suspected pregnancy, current breast cancer
- CautionSevere hepatic disease
Side effects
- Irregular bleeding (main reason for removal)
- Headache
- Acne
- Mood change
- Weight gain (modest)
Fetal & maternal notes
- • Remove immediately if pregnancy confirmed — no known teratogenicity
Key interactions
Enzyme inducers (rifampicin, phenytoin, carbamazepine, St John's wort)
Avoid↓ efficacy — add barrier or switch to Cu-IUD/DMPA
Clinical pearls
- 💡 Ultrasound / MRI to locate deeply inserted implants before removal
- 💡 Bleeding pattern in first 3 months predicts long-term pattern
Content last reviewed: REPLACE_ME (e.g. 2026-07)
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