Progestogen-only contraceptive implant Pregnancy: Not indicated during pregnancy; if pregnancy occurs during use, the implant should be removed. May be used during lactation (small amounts of etonogestrel are excreted in breast milk; development and growth of the child should be followed).

Etonogestrel

Brand names: Nexplanon, Implanon NXT

A progestogen used for long-acting reversible contraception, available as a subdermal implant and as the active progestogen in some combined hormonal and vaginal ring products.

Auto-extracted from the source labelling — not yet independently clinician-verified. These values were distilled from the UK SPC (or the US label where noted) but have not had a clinician sign-off. Confirm against the current SmPC before prescribing.

Adult dose

Dose: 1 implant (68 mg)

Route: subdermal

Frequency: single implant, left in place for up to 5 years

Nexplanon 68 mg subdermal implant. A single implant is inserted subdermally just under the skin at the inner side of the non-dominant upper arm and can be left in place for five years; remove no later than five years after insertion. Pregnancy must be excluded before insertion. Insertion/removal only by trained healthcare professionals. Timing of insertion depends on the woman's recent contraceptive history (e.g. no preceding hormonal contraceptive: insert between Day 1 and Day 5 of the menstrual cycle). After removal, immediate insertion of another implant continues contraceptive protection.

Dose auto-extracted from UK Summary of Product Characteristics (SPC) via the eMC; US FDA prescribing information (openFDA / DailyMed) — cross-check; US labelling may differ from UK — not yet clinician-verified. Always confirm against the product SmPC and your local formulary before prescribing.

Contraindications

Active venous thromboembolic disorder
Known or suspected sex steroid-sensitive malignancies
Presence or history of liver tumours (benign or malignant)
Presence or history of severe hepatic disease as long as liver function values have not returned to normal
Undiagnosed vaginal bleeding
Hypersensitivity to the active substance or to any of the excipients

Side effects

Changes in menstrual bleeding pattern (amenorrhoea, irregular, frequent, prolonged or heavy bleeding) — very common; most common reason for stopping treatment
Headache — common
Acne — common
Breast tenderness / breast pain — common
Weight increased — common

Interactions

Enzyme-inducing drugs/herbal products (e.g. CYP3A4 inducers) may reduce effectiveness or increase breakthrough bleeding — use back-up or alternative contraception (examples include phenytoin, barbiturates, carbamazepine, rifampicin, and St. John's wort)

Clinical monograph

How it works

It inhibits ovulation, thickens cervical mucus and alters the endometrium, preventing fertilisation and implantation.

Prescribing in practice

Contraindicated in active venous thromboembolism and in current or past breast cancer; exclude pregnancy before insertion.
The implant must be correctly inserted and located subdermally; impalpable or deep implants require imaging and specialist removal.
Irregular or unpredictable bleeding is common and is a frequent reason for discontinuation; counsel beforehand.

Monitoring

Check the implant is palpable after insertion and review bleeding pattern, blood pressure and contraceptive needs periodically.

Counselling the patient

Bleeding patterns often change and may be irregular, especially at first.
The implant provides long-acting contraception but does not protect against sexually transmitted infections.
Note the insertion date and when replacement or removal is due.

Evidence & guidelines

Long-acting reversible contraception including the progestogen implant is recommended as highly effective by NICE.

Reference: FSRH CEU guidance; NICE CKS; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Curated clinical cross-links plus same-class fallbacks.

Calculators

Pathways