Known brand names include Scenesse.
An implant placed under the skin every 2 months for adults with erythropoietic protoporphyria, a rare inherited disorder in which sunlight causes burning skin pain. It darkens the skin by boosting the body's own pigment, which lets people spend more time in daylight without pain.
Afamelanotide is a synthetic copy of alpha-melanocyte stimulating hormone, a natural hormone that tells pigment cells in the skin to make melanin. It binds mainly to the melanocortin 1 receptor on those cells. That switches on production of eumelanin, the dark brown pigment, without any need for sunlight or tanning lamps. The rod is a controlled-release implant, so the peptide enters the blood slowly instead of all at once.
Implant under the skin (1/7)
A small rod is implanted under the skin above the hip, every 2 months.
In healthy volunteers, blood levels of the peptide peaked around 36 hours after the implant went in and were mostly gone by 96 hours, with an apparent half-life of about 15 hours. The dosing interval is still every 2 months, because the pigment it builds lasts far longer than the drug itself stays in the blood. The same receptor signal darkens existing moles and freckles, which is why skin checks are part of treatment. How the body breaks it down has not been fully worked out, and no drug interaction studies have been done.
Afamelanotide is a small rod implanted under the skin for adults with erythropoietic protoporphyria, a rare inherited condition in which a light-sensitive chemical builds up in the skin and sunlight triggers burning pain and swelling. It increases the amount of time these patients can spend in daylight without a painful reaction. In trials, people treated with it spent more pain-free hours in direct sunlight than people given a blank implant. It does not cure the underlying disorder, so sun and light protection continue during treatment.
A trained healthcare professional inserts one implant above the hip bone every 2 months using a special cannula, and the patient is watched for 30 minutes afterward. It is sold as Scenesse and dissolves on its own, though it can be removed if a serious reaction occurs. Because it darkens skin and moles, patients need a full skin examination twice a year. It has not been studied in children, and only a few patients over 65 were included in the trials.
Bruising, soreness, discoloration, or a lump where the implant sits, nausea, sore throat, cough, and tiredness are what people notice most. Darker skin and new or darker moles follow from how the drug works, along with dizziness and sleepiness in some people. The label treats allergic reactions as serious, and anaphylaxis has been reported since approval, in which case the implant may be removed. It also asks for a full skin check twice a year, because existing moles and freckles darken and new pigmented spots need watching.
A clinician may order these while someone is taking it.
Sources: [1]