Melanotan-1 (MT-1)
Cosmetic and Skincare
ABOUT
Melanotan-1 (MT-1), now known pharmaceutically as afamelanotide, is an MC1R agonist. The approved Scenesse formulation is a 16 mg subcutaneous implant used to increase pain-free light exposure in adults with erythropoietic protoporphyria; that approval does not establish unregulated injectable products as equivalent.
EVIDENCE OVERVIEW
Supported by controlled human trials
WHAT THIS MEANS
Established. Review the research and limitations before relying on this record.
IDENTITY
HALF-LIFE
HOW IT IS THOUGHT TO WORK
A synthetic tridecapeptide analogue of alpha-melanocyte-stimulating hormone acting as an MC1R agonist. It stimulates melanogenesis, specifically eumelanin production in the epidermis. In erythropoietic protoporphyria, accumulated protoporphyrin IX reacts with light to cause phototoxic pain; increased eumelanin is the photoprotective mechanism. It is comparatively receptor-selective, unlike melanotan II.
PHARMACOKINETICS
Supplied as a 16 mg bioresorbable implant roughly 1.7 cm long, inserted subcutaneously above the anterior supra-iliac crest every two months by a trained healthcare professional. Pharmacokinetics were evaluated in 12 healthy adults with high variability; in 9 of 12 the last measurable concentration was limited. The effect of renal or hepatic impairment is unknown and no drug-interaction or carcinogenicity studies were conducted.
REVIEW
PUBLISHED PAIR RECORDS
with PT-141
Shared melanocortin-receptor activityPT-141 and Afamelanotide are both melanocortin-receptor agonists, so they converge on the same receptor family rather than on separate mechanisms - but they are not interchangeable within it: bremelanotide is comparatively selective, acting principally at MC4 and MC1, and is approved for a single defined indication; afamelanotide is an MC1-receptor agonist supplied as a bioresorbable implant, approved for erythropoietic protoporphyria, whose labelling records that no drug-interaction studies were conducted and that twice-yearly skin examination is recommended because it darkens existing naevi. Overlapping activity at MC1 drives pigmentary effects and at MC4 drives appetite, sexual and cardiovascular effects, so which receptors a pair shares determines which effects stack. No study has characterised any two of these given together. Peppy reports curated pharmacology, not a safety verdict. A prescriber or pharmacist should review any intended combination.
Reviewed 21 Aug 2026with Melanotan II
Shared melanocortin-receptor activityMelanotan II and Afamelanotide are both melanocortin-receptor agonists, so they converge on the same receptor family rather than on separate mechanisms - but they are not interchangeable within it: melanotan II is non-selective across melanocortin receptors, has never been submitted for regulatory review, and carries a published case literature of priapism, rhabdomyolysis with acute kidney injury, renal infarction and melanocytic change; afamelanotide is an MC1-receptor agonist supplied as a bioresorbable implant, approved for erythropoietic protoporphyria, whose labelling records that no drug-interaction studies were conducted and that twice-yearly skin examination is recommended because it darkens existing naevi. Overlapping activity at MC1 drives pigmentary effects and at MC4 drives appetite, sexual and cardiovascular effects, so which receptors a pair shares determines which effects stack. No study has characterised any two of these given together. Peppy reports curated pharmacology, not a safety verdict. A prescriber or pharmacist should review any intended combination.
Reviewed 21 Aug 2026with Setmelanotide
Shared melanocortin-receptor activityAfamelanotide and Setmelanotide are both melanocortin-receptor agonists, so they converge on the same receptor family rather than on separate mechanisms - but they are not interchangeable within it: afamelanotide is an MC1-receptor agonist supplied as a bioresorbable implant, approved for erythropoietic protoporphyria, whose labelling records that no drug-interaction studies were conducted and that twice-yearly skin examination is recommended because it darkens existing naevi; setmelanotide is a selective MC4-receptor agonist approved for defined melanocortin-pathway obesity, whose labelling records that no dedicated drug-interaction studies have been conducted. Overlapping activity at MC1 drives pigmentary effects and at MC4 drives appetite, sexual and cardiovascular effects, so which receptors a pair shares determines which effects stack. No study has characterised any two of these given together. Peppy reports curated pharmacology, not a safety verdict. A prescriber or pharmacist should review any intended combination.
Reviewed 21 Aug 2026HUMAN EVIDENCE
Early phase 1 studies used the name Melanotan-1 and tested short courses of subcutaneous peptide with ultraviolet light or sunlight in small groups of healthy volunteers; they found increased tanning, with nausea and transient facial flushing reported. The evidence that led to approval belongs to a different presentation: two multicentre randomised double-blind placebo-controlled trials used a 16 mg afamelanotide implant every 60 days in 74 European and 94 U.S. adults with erythropoietic protoporphyria. Pain-free sunlight exposure increased, and FDA approved the implant on 8 October 2019. These findings establish the labelled implant for EPP, not the identity, exposure or safety of unregulated MT-1 vials.
REPORTED EFFECTS
Common adverse reactions above 2% include implant-site reaction, nausea, oropharyngeal pain, cough, fatigue, dizziness, skin hyperpigmentation, somnolence, melanocytic naevus, respiratory tract infection, non-acute porphyria and skin irritation. Serious hypersensitivity including anaphylaxis has been reported post-marketing. Because it darkens pre-existing naevi and ephelides, twice-yearly full-body skin examination is recommended - the same melanocytic concern that dominates the melanotan II case literature, here handled by required monitoring.
RESEARCH LIMITATIONS
This is a source-backed summary, not a recommendation. Read the mechanism, pharmacokinetic, human-evidence and reported-effect fields separately: a mechanism is not an outcome. Availability, legal status and product quality differ by jurisdiction; consult a qualified clinician.
CURATED SOURCES · 5