What Is Afamelanotide (Scenesse)? The Tanning Peptide Implant for Light Sensitive Porphyria and What Its Trials Found

Afamelanotide, sold as Scenesse, is a synthetic peptide that darkens your skin from the inside. It copies alpha-MSH (alpha melanocyte stimulating hormone), the body's own signal for making melanin, and it is delivered as a small implant placed under the skin every two months. The [FDA label on DailyMed](https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=94f53286-11dd-7fbb-e053-2a95a90a7c48) lists an initial U.S. approval in 2019, for adults with erythropoietic protoporphyria (EPP), a rare inherited condition in which visible light causes intense, burning pain within minutes.

Afamelanotide matters to anyone following peptide research for a second reason, because it is the regulated, studied cousin of the unregulated tanning peptides sold online, such as [Melanotan II](/articles/melanotan-2-guide). It shows what a melanocortin peptide can do when it is made to pharmaceutical standards, tested against placebo, and given to the one group of patients for whom extra pigment is a medical need rather than a cosmetic one. This article covers how afamelanotide works, what its trials found, how it is dosed and what its label says about safety. It is educational content about published research, not medical advice.

Erythropoietic protoporphyria is an inherited disorder of heme production in which a compound called protoporphyrin builds up in the blood and skin. When visible light hits skin loaded with protoporphyrin, the molecule absorbs that light and triggers a phototoxic reaction, a burning, stabbing pain that can last for days and often comes with little visible redness.

EPP is rare. A Swiss research group puts its prevalence at about 1 in 150,000 ([Barman-Aksözen, Orphanet Journal of Rare Diseases, 2020](https://doi.org/10.1186/s13023-020-01505-6)), and a German study team writes that it affects at least one in 140,000 Europeans ([Homey, Photodermatology, Photoimmunology and Photomedicine, 2025](https://doi.org/10.1111/phpp.13012)). Because the pain often arrives without a visible burn, many patients go years without a diagnosis, and most learn to organize their lives around avoiding daylight.

The NEJM trial authors describe patients who "have excruciating pain and a markedly reduced quality of life." Before afamelanotide, there was no approved treatment that prevented the reactions, so patients relied on staying indoors and wearing protective clothing, because ordinary sunscreens block UV rather than the visible light that drives EPP.

Afamelanotide works by switching on melanin production without sunlight. The Scenesse label describes it as a synthetic tridecapeptide, a 13 amino acid structural analog of alpha-MSH that binds predominantly to MC1-R, the receptor on your melanocytes that controls which kind of melanin the skin makes.

When MC1-R is activated, melanocytes shift toward eumelanin, the dark brown to black pigment that absorbs and scatters light. The label states that afamelanotide "increases production of eumelanin in the skin independently of exposure to sunlight or artificial UV light sources." In EPP, that extra eumelanin acts as an internal filter, reducing how much light reaches the protoporphyrin in the skin.

Afamelanotide is not an exact copy of the natural hormone. The structure printed in the label includes norleucine (Nle) and a D-phenylalanine, building blocks that do not appear in human alpha-MSH, and changes like these are a common way to help a peptide hold up longer in the body than the hormone it imitates.

Afamelanotide, Melanotan II and [PT-141 (bremelanotide)](/articles/pt-141-bremelanotide) all come from the same family of melanocortin peptides, but they act on different receptors and have very different regulatory standing.

Afamelanotide binds mainly to MC1-R, the pigment receptor, and is a full length linear analog of alpha-MSH. Melanotan II and bremelanotide are shorter, ring shaped peptides that also act on MC3-R and MC4-R in the brain, which is why they are linked to appetite changes, nausea and effects on sexual arousal. Melanotan II is sold online as an unregulated research chemical rather than as an approved medicine.

The practical difference for you is that afamelanotide's effects, doses and side effects come from controlled trials and an FDA label, while claims about tanning peptides bought online do not. The data in this article apply to Scenesse, made and dosed as labeled, and should not be transferred to unregulated products. For another approved melanocortin drug that targets the brain's MC4-R instead, see our article on [setmelanotide (Imcivree)](/articles/setmelanotide-mc4r-agonist-genetic-hypothalamic-obesity).

Both phase 3 trials of afamelanotide met their primary endpoint, giving patients more time in direct sunlight without pain than a placebo implant. The evidence comes from two randomized, double blind, placebo controlled trials published together in the New England Journal of Medicine ([Langendonk, NEJM, 2015](https://doi.org/10.1056/NEJMoa1411481)). One enrolled 74 patients in the European Union and the other enrolled 94 patients in the United States. Patients received a 16 mg afamelanotide implant or a placebo implant every 60 days, for a total of five implants over about 9 months in the European study and three implants over about 6 months in the U.S. study.

The primary endpoint was the number of hours patients spent in direct sunlight without pain, recorded in daily diaries, and both trials met it. In the U.S. study, median pain free time over 6 months was 69.4 hours with afamelanotide versus 40.8 hours with placebo (P=0.04). In the European study, median pain free time over 9 months was 6.0 hours versus 0.8 hours (P=0.005), and the number of phototoxic reactions was lower with afamelanotide, at 77 versus 146 on placebo. Quality of life improved with afamelanotide in both trials, and the authors reported that adverse events were mostly mild, with serious adverse events not thought to be related to the study drug.

Two features of these results deserve a plain reading. First, the absolute numbers look small, because patients with EPP avoid light by long habit, so even treated patients did not suddenly spend whole days outdoors during a trial. Second, the placebo group in the U.S. study still logged a median of 40.8 pain free hours, which suggests that behavior and season shape this endpoint as much as the drug does. The trials were funded by Clinuvel, the drug's maker, alongside other funders.

Real world cohorts suggest that afamelanotide's benefit holds up over years of routine use. Three cohorts from European porphyria centers report consistent results, although they measured different outcomes from the trials and none of them has a placebo group.

Italy and Switzerland. A long term observational study followed 115 patients treated with a total of 1023 implants over up to 8 years at centers in Rome and Zurich ([Biolcati, British Journal of Dermatology, 2015](https://doi.org/10.1111/bjd.13598)). Scores on an EPP specific quality of life questionnaire were 31% of maximum before treatment and rose to 74% after starting afamelanotide, staying at that level through the observation period. By June 2014, 66% of all known EPP patients at those centers were being treated, while 23% stopped for other reasons, mostly pregnancy or cost, and only minor adverse events, mainly nausea, were linked to the drug.

Switzerland. A three year study of 39 patients in the Swiss EPP cohort measured how long people could stay in sunlight before a reaction ([Barman-Aksözen, Orphanet Journal of Rare Diseases, 2020](https://doi.org/10.1186/s13023-020-01505-6)). Before treatment, the median was 10 minutes, and on treatment it rose to 180 minutes. The pain of the worst reaction fell from a median of 10 to 6 on a 0 to 10 scale, quality of life at the end of the study was 81.4%, and treatment adherence was 97.4%. The authors reported no competing interests.

Germany. A post authorization safety study required by the European regulator followed 200 treated patients in Germany ([Homey, Photodermatology, Photoimmunology and Photomedicine, 2025](https://doi.org/10.1111/phpp.13012)). Quality of life rose significantly from baseline, and 91.0% of patients who started treatment were still on it. Several authors received research support from Clinuvel or are employed by the company, which you should weigh when reading the result.

Scenesse is dosed as one 16 mg implant every 2 months, inserted under the skin above the front of the hip bone (the label calls it the anterior supra iliac crest). The label says a healthcare professional trained in the implantation procedure should place it, using a dedicated implantation cannula.

The implant is a solid, bioresorbable rod about 1.7 cm long and 1.45 mm in diameter. Each one contains 16 mg of afamelanotide (equivalent to 18 mg of afamelanotide acetate) mixed into a poly(lactide co glycolide) polymer, a slowly dissolving material, so there is nothing to remove under normal use because the rod dissolves on its own.

The label also tells patients to keep up sun and light protection during treatment, because afamelanotide raises the threshold for a reaction rather than eliminating the disease.

Afamelanotide itself does not last long in the blood. According to the label, its apparent half life from the implant is about 15 hours, with a median time to peak concentration of 36 hours, and in a study of 12 healthy adults the last measurable level was at 96 hours after insertion in 9 of the 12.

That short presence in the blood is not the same as a short effect, because the pigment the drug induces builds up in the skin and fades slowly, which is why the implant is given every two months rather than every few days. For more on why a peptide's half life and its dosing interval can differ, see our guide to [peptide half life and dosing frequency](/articles/peptide-half-life-dosing-frequency).

The most common side effects of afamelanotide are implant site reactions and nausea. The label pools 3 vehicle controlled trials with 244 adults with EPP, in which 125 received Scenesse and 119 received a vehicle implant, and reports adverse reactions through month 6. Implant site reactions occurred in 21% on Scenesse versus 10% on vehicle, and nausea in 19% versus 14%. Within the implant site reactions, the most common was discoloration at the implant site, at 10% in the Scenesse group.

The label lists two warnings. The first is skin pigmentation, since afamelanotide may cause generally darker skin and darkening of existing moles and freckles, so the label recommends a full body skin examination twice yearly to track existing and new pigmented spots. The second is hypersensitivity, because serious allergic reactions, including anaphylaxis, have been reported since approval, and anyone who has one should not receive the drug again.

According to the label, there are no data on afamelanotide use in pregnant women, and the effect of kidney or liver impairment on how the drug is handled is unknown.

Afamelanotide is not approved for vitiligo, but it has been tested in one randomized trial ([Lim, JAMA Dermatology, 2015](https://doi.org/10.1001/jamadermatol.2014.1875)). Adults with nonsegmental vitiligo covering 15% to 50% of their body received narrowband UVB light therapy, either alone (27 patients) or combined with 16 mg afamelanotide implants given monthly for 4 months (28 patients).

At day 168, repigmentation was 48.64% in the combination group versus 33.26% with light therapy alone, and repigmentation on the face started sooner with the combination, at 41.0 days versus 61.0 days. The benefit showed up in people with darker skin types (Fitzpatrick IV to VI) and not in skin type III. This was a small trial, and vitiligo remains an investigational use rather than an approved one.

Afamelanotide is a prescription drug supplied as an implant through specialist centers, and its evidence comes from controlled trials and regulatory review rather than from the gray market. That makes it a useful reference point when you evaluate claims about unregulated melanocortin peptides, because the effects, side effects and monitoring described here were measured with the approved product at a fixed 16 mg dose. None of these results establish safety or benefit for injectable tanning products sold online, which are not made to the same standards and have not been tested in the same way.

Afamelanotide is one of the clearest examples of a melanocortin peptide doing exactly what its biology predicts, because it builds eumelanin in the skin and, for people with EPP, that pigment buys real time in daylight. The randomized trials showed a modest but significant gain in pain free sun exposure, and the European cohorts suggest the benefit holds up over years, with high adherence and side effects that are mostly implant site reactions and nausea. If you are curious about tanning peptides, the most useful lesson from Scenesse is how much testing, dosing control and skin monitoring an approved melanocortin drug still requires.