Afamelanotide is one of the few peptides in this family that cleared a full regulatory review. The US Food and Drug Administration approved it in October 2019 under the brand name Scenesse, and the European Medicines Agency had already authorized it in late 2014. The indication is narrow: increasing pain-free light exposure in adults with erythropoietic protoporphyria (EPP), a rare inherited disorder that makes skin react painfully to light. It is made by the Australian company Clinuvel.
Chemically it is a synthetic 13-amino-acid analogue of alpha-melanocyte-stimulating hormone (α-MSH), often written as [Nle4, D-Phe7]-α-MSH or NDP-α-MSH. Swapping in those two modified residues makes the peptide resist the enzymes that break down natural α-MSH, so it stays active far longer.
A naming knot worth untangling
Afamelanotide is the same molecule that early research called melanotan-I. That shared history causes real confusion. The peptides sold online as "Melanotan" or "Melanotan II" for tanning are not the approved drug. Melanotan II in particular is a different, more potent compound that has never been approved as a medicine and has been the subject of safety warnings from regulators in several countries. So while "Melanotan" appears in afamelanotide's list of synonyms, the approved EPP implant and the grey-market tanning injectables are not interchangeable.
How it works
Afamelanotide is a melanocortin-1 receptor (MC1R) agonist. By binding MC1R on melanocytes, it drives production of eumelanin, the darker pigment in skin, without needing ultraviolet exposure to trigger it. In EPP, patients accumulate a light-reactive molecule called protoporphyrin IX because of reduced activity of the enzyme ferrochelatase. When that builds up in skin and meets light, it sets off a phototoxic reaction and severe pain. The extra eumelanin afamelanotide produces acts as a sunscreen of sorts, absorbing and scattering light before it can do as much damage. The FDA describes the result as photoprotection produced independently of sun exposure.
What the trials showed
The pivotal evidence comes from two randomized, double-blind, placebo-controlled trials published together in the New England Journal of Medicine in 2015, one run in the European Union and one in the United States. Patients received a subcutaneous implant containing 16 mg of afamelanotide, or placebo, every 60 days.
In the US study (CUV039, 93 patients), the primary endpoint was hours spent in direct sunlight on days without pain over six months. The afamelanotide group recorded a median of about 64 hours versus about 41 hours on placebo. The EU trial pointed the same direction. The most common adverse effects reported were implant-site reactions, nausea, and headache, with no serious drug-related toxicities flagged in those trials.
The approved regimen is a single 16 mg implant placed under the skin near the hip every two months, administered by a trained clinician. It is a prescription product, not something self-administered from a vial.
Beyond EPP
Researchers have studied afamelanotide in other conditions, including vitiligo, where small trials combined it with narrowband UVB phototherapy, plus polymorphous light eruption, solar urticaria, and xeroderma pigmentosum. There has also been early-stage work in acute ischemic stroke. These uses remain investigational; the only approved indication is EPP.
For buyers and the testing angle
Research-grade "afamelanotide" sold as a lyophilized powder is a different thing from the approved Scenesse implant. It is not a pharmaceutical product, carries no approval for human use, and is sold for laboratory research only. Because the name overlaps with the Melanotan tanning peptides, mislabeling and identity errors are a genuine concern in this corner of the market. If you are evaluating a vendor's powder, the facts that actually matter are independent ones: a recent third-party certificate of analysis confirming identity and purity by HPLC and mass spectrometry, and lot-level testing rather than a generic document. The vendor ratings this site aggregates exist to surface exactly that kind of independent verification.
Nothing here is medical or dosing advice. Afamelanotide as a research chemical is not approved for human consumption, and the approved drug is prescribed and implanted by clinicians for a specific rare disease.