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FDA Approved

Melanotan I (Afamelanotide)

Skin, Hair & Beauty · ['Afamelanotide', 'Melanotan-1', 'MT-1', 'Scenesse', '[Nle4-D-Phe7]-alpha-MSH']

A synthetic analog of alpha-melanocyte-stimulating hormone (alpha-MSH) that acts as a melanocortin-1 receptor agonist studied for its effects on eumelanin production. Afamelanotide is an FDA-approved active ingredient (Scenesse) for a rare photosensitivity condition; it is also widely encountered as a research peptide.

🔬 Research use only — not for human or veterinary use. K4 Elite does not provide dosing instructions.
Molecular Formula
C78H111N21O19
Molecular Weight
1646.8 g/mol
PubChem
CID 16197727 ↗
Research Level
FDA Approved
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Melanotan I (Afamelanotide) chemical structure

Melanotan I, known by the international nonproprietary name afamelanotide, is a synthetic 13-amino-acid analog of the naturally occurring hormone alpha-melanocyte-stimulating hormone (alpha-MSH). It carries two substitutions from the native sequence (norleucine at position 4 and D-phenylalanine at position 7) that increase its metabolic stability and receptor potency relative to native alpha-MSH.

PubChem lists afamelanotide under CID 16197727, with molecular formula C78H111N21O19 and a molecular weight of approximately 1646.8 g/mol. As a melanocortin agonist, it is studied primarily for its influence on melanin synthesis in melanocytes. Afamelanotide is also a regulatory-approved active ingredient: it received FDA approval (as Scenesse) for reducing phototoxicity in adults with erythropoietic protoporphyria, and it holds European approval for the same indication.

This entry is provided for laboratory and educational reference only and describes published research and regulatory findings. It does not constitute medical advice or a recommendation for human or veterinary use.

Afamelanotide is characterized as an agonist at the melanocortin-1 receptor (MC1R), a G-protein-coupled receptor expressed on melanocytes. Binding is described as activating adenylate cyclase, raising intracellular cyclic AMP, and increasing microphthalmia-associated transcription factor (MITF) activity, which upregulates enzymes of melanogenesis such as tyrosinase. The net reported effect in studies is a shift toward increased eumelanin production.

Because eumelanin absorbs and dissipates ultraviolet and visible light, the mechanism underlying its approved indication is framed as photoprotective: increased melanin is proposed to reduce phototoxic reactions in individuals with erythropoietic protoporphyria. Afamelanotide is relatively MC1R-selective compared with the broader melanocortin activity of some related analogs.

  • Melanogenesis and MC1R signaling — afamelanotide has been studied as an MC1R agonist driving eumelanin synthesis (Hadley & Dorr, 2006).
  • Erythropoietic protoporphyria — randomized controlled trials evaluated afamelanotide for phototolerance in this rare disorder (Langendonk et al., 2015, NEJM).
  • Photoprotection — research has examined melanin-mediated reduction of UV/visible-light phototoxicity.
  • Regulatory pharmacology — the compound has an established FDA and EMA approval record supporting its pharmacological profile.
  • Dermatologic photosensitivity disorders — investigational use has extended to other light-sensitivity conditions in the literature.
📋 How published studies were conducted — a research reference summarizing study designs from the literature. This is not usage, dosing, or administration guidance. K4 Elite does not provide dosing instructions; determining any research protocol is the sole responsibility of the qualified researcher.

Langendonk et al. (2015), published in the New England Journal of Medicine, reported two randomized, placebo-controlled trials of afamelanotide delivered as a subcutaneous implant in adults with erythropoietic protoporphyria; the studies measured pain-free time in sunlight and related phototolerance endpoints and reported increases relative to placebo. This is described here to report what the trials did and found, not as guidance.

Earlier pharmacology work summarized by Hadley & Dorr (2006) characterized the melanotropic potency and receptor selectivity of the [Nle4-D-Phe7]-alpha-MSH structure in laboratory and animal systems. The doses, routes and delivery formats used in these studies are properties of the published research and are not provided here as recommendations.

Combinations examined in the research literature. Descriptive only — not a recommendation to combine compounds.

Melanotan IICaution
A related but less MC1R-selective analog studied separately; the two are distinct research compounds and should not be conflated.
UV/visible light exposureSynergistic
Melanin's photoprotective effect is studied in the context of light exposure, which is the basis of the approved-indication research.
Alpha-MSH (native)Compatible
Afamelanotide is a stabilized analog of native alpha-MSH; both act on melanocortin receptors.
Other MC1R ligandsNeutral
Co-administration with other melanocortin-receptor ligands is not characterized in the reference literature.
  1. PubChem CID 16197727 (Afamelanotide)
  2. Langendonk et al., Afamelanotide for erythropoietic protoporphyria (2015), N Engl J Med
  3. Hadley & Dorr, Melanocortin peptide therapeutics (2006), Peptides
  4. FDA Scenesse (afamelanotide) approval label
What is Melanotan I chemically?
It is afamelanotide, a synthetic 13-amino-acid analog of alpha-MSH with norleucine and D-phenylalanine substitutions. PubChem CID 16197727, formula C78H111N21O19, molecular weight about 1646.8 g/mol.
Is Melanotan I FDA approved?
Afamelanotide (as Scenesse) is FDA approved for reducing phototoxicity in adults with erythropoietic protoporphyria. That approval is specific to that indication and delivery format.
How is it thought to work?
It is described as an MC1R agonist that raises cyclic AMP and MITF activity, increasing eumelanin production in melanocytes.
How does it differ from Melanotan II?
Melanotan I (afamelanotide) is more selective for MC1R, whereas Melanotan II has broader melanocortin-receptor activity. They are distinct research compounds.
Can I use this material as a supplement or cosmetic?
No. This entry is for research and educational reference only. It is not a product description or recommendation for human or veterinary use and contains no dosing guidance.
Disclaimer: This profile summarizes published preclinical and laboratory research for reference only. It is not medical advice and makes no claim of safety or efficacy in humans. Determining any research protocol is the sole responsibility of the qualified researcher. Products are sold strictly for in-vitro research and have not been evaluated by the FDA.