Etonogestrel implant rod: what it is and how it works

The etonogestrel implant rod is a small flexible device that releases a progestogen under the skin of the upper arm.

A trained clinician places the rod beneath the skin. It releases etonogestrel gradually into the bloodstream. The hormone mainly prevents ovulation and thickens mucus at the cervix, which helps prevent sperm from reaching an egg. The rod is not an oestrogen-containing method.

Because the rod releases hormone continuously, there is no daily pill to remember. Bleeding may become lighter, less frequent, more frequent or unpredictable, especially after insertion. Changes in acne, mood, headaches or breast tenderness can occur, although experiences vary. The implant does not protect against sexually transmitted infections, so another method may be needed for that purpose.

The rod is used for long-acting reversible contraception. Insertion usually involves local anaesthetic and a small procedure in the upper arm. A clinician checks its position afterward and explains wound care. Removal is also a clinical procedure. Fertility can return quickly after removal, so discuss another contraceptive method if pregnancy is not planned.

Alternatives include a hormonal intrauterine device, an injection, progestogen-only pills, combined pills, copper intrauterine contraception and barrier methods. These choices differ in bleeding patterns, hormones, procedure needs and how quickly a person can stop them. A consultation can match the method to your preferences and medical history.

A rod in the arm may be felt as a firm, thin strip beneath the skin. Contact the clinic if you cannot feel it, the insertion area becomes increasingly red or painful, or the rod appears to be moving. Seek urgent care for severe allergic symptoms or significant arm swelling. Unpredictable bleeding is a known effect, but heavy or persistent bleeding should be assessed.

Keep a record of when the implant was inserted and when it should be reviewed or replaced according to the product and local clinical advice. Some medicines and herbal products can reduce the contraceptive effect. Tell every prescriber that you have an implant, and arrange review if you start regular treatment, develop a new health condition or want to plan a pregnancy.