Melanotan 2

What Melanotan-II Is

Melanotan-II (MT-II) is a 7-residue cyclic heptapeptide (Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-NH₂, cyclized via Asp-Lys lactam bridge; molecular formula C₅₀H₆₉N₁₅O₉; MW 1024.18 Da; CAS 121062-08-6; ChEMBL CHEMBL1822; PubChem CID 5024411; Wikidata Q1881587). It is derived from the active core of alpha-melanocyte-stimulating hormone (alpha-MSH) and acts as a non-selective agonist at MC1R, MC3R, MC4R, and MC5R melanocortin G-protein-coupled receptors. The class distinguishes MT-II from the MC3R/MC4R-selective cyclic alpha-MSH(4-10) analog bremelanotide (PT-141), and from the linear 13-amino-acid alpha-MSH analog afamelanotide (Scenesse®).

Important Regulatory Disambiguation

Melanotan-II is NOT afamelanotide / Scenesse®. Afamelanotide (Scenesse®, Clinuvel Pharmaceuticals) is a linear 13-amino-acid alpha-MSH analog FDA-approved in October 2019 for adult erythropoietic protoporphyria. Afamelanotide is structurally distinct from MT-II (different sequence, different length, different cyclization) and has a different regulatory status. Artemis Labs does NOT market, NOT substitute for, and NOT reference clinical indications of afamelanotide or Scenesse®. Our MT-II is a research-grade lyophilized peptide for in vitro and IACUC-approved animal research only. Several U.S. state Boards of Pharmacy have issued advisories against compounding melanotan products for cosmetic use; Artemis Labs PT-141, MT-II, and the broader research catalog are supplied strictly as research reagents – not as compounded pharmaceuticals and not as tanning, cosmetic, or self-administered preparations.

The Two Distinct alpha-MSH-Analog Compounds

Why It Is Studied – 2025-2026 Research Refinements

• Adverse-event documentation – Resnick et al. 2026 (PMID 41890775): tanning-biology review explicitly documents unregulated Melanotan I/II adverse events including rhabdomyolysis, renal infarction, and priapism. Cited by Artemis as a primary reason for the research-only positioning.
• Persistent gingival pigmentation case report – Bonchev 2026 (PMID 41752902): brown maxillary and mandibular gingival pigmentation following self-administered MT-II injections, persisting at least 3 months after discontinuation. Cited as a documented adverse-event signal.
• Public-health signal – Sidhu et al. 2026 (PMID 41559011): social-media-driven unregulated MT-II misuse linked to ‘looksmaxxing’ and body-image culture as an emerging dermatologic and public-health risk.
• Class-level stability mapping – Chawathe & Sharma 2026 (PMID 41547183): LC-HRMS analytical framework mapping 14 distinct degradation products of afamelanotide under acidic, basic, neutral, oxidative, UV, and thermal stress. Directly applicable to MT-II’s purity verification as alpha-MSH-class context.
• Sustained-release alpha-MSH-class delivery – Anderson et al. 2026 (PMID 41999898): stereocomplexed beta-strand/hairpin hydrogel releasing alpha-MSH-analog peptide over months. Class-level PK innovation cited as alpha-MSH-class context only – not as MT-II protocol.

How Artemis Labs Sources and Verifies Melanotan-II

Each lot is supplied as a sterile lyophilised peptide powder, analytically verified by reverse-phase HPLC to ≥99% peptide purity, with identity confirmed by mass spectrometry. The compound shipped is the canonical 7-mer cyclic Ac-Nle-Asp-His-D-Phe-Arg-Trp-Lys-NH₂ sequence with Asp-Lys lactam closure. A third-party Certificate of Analysis with HPLC chromatogram, MS identity, residual-solvent assay, and endotoxin testing is available on request. The 2026 Chawathe & Sharma LC-HRMS degradation map (PMID 41547183) is the relevant alpha-MSH-class analytical reference for ongoing purity verification work.

Honest Limitations of the MT-II Evidence Base

(1) Documented adverse-event signal from unregulated use. The 2026 dermatology literature (PMID 41890775, PMID 41752902, PMID 41559011) documents rhabdomyolysis, renal infarction, priapism, persistent gingival pigmentation, and social-media-driven misuse. These findings strengthen the case for research-only positioning. (2) Mechanistically related to but not equivalent to afamelanotide. Both are alpha-MSH analogs but they are different molecules (cyclic vs linear; 7-aa vs 13-aa; non-selective vs the afamelanotide profile). Afamelanotide clinical findings do not transfer to MT-II positioning. (3) Not FDA-approved in any formulation. Several U.S. state Boards of Pharmacy have issued compounding advisories. (4) Non-selective receptor profile creates broad systemic effects. Compared with MC3R/MC4R-selective bremelanotide (PT-141), MT-II’s non-selective activation across MC1R-MC5R produces a broader effect profile that is studied in the preclinical literature as a feature of the compound class, not as a clinical advantage.

Class Positioning

Unlike PT-141 (selective MC3R/MC4R cyclic alpha-MSH(4-10) analog with FDA-approved active ingredient in the Vyleesi® product), MT-II is non-selective across MC1R-MC5R and is not FDA-approved in any formulation. Unlike oxytocin (9-aa cyclic OXTR-agonist neuropeptide), MT-II acts through the broader melanocortin receptor family. The 2024 Inozemtseva et al. (PMID 39442746) paper directly compared MT-II vs Semax antidepressant/antistress effects in chronic stress models – see Semax for the mechanism-comparator citation.

Regulatory and Compliance Framing

Melanotan-II is NOT FDA-approved, NOT EMA-approved, and NOT DEA-scheduled. Afamelanotide / Scenesse® (a different molecule) is FDA-approved for adult erythropoietic protoporphyria – this approval does not transfer to MT-II. Several U.S. state Boards of Pharmacy have issued advisories against compounded melanotan products for cosmetic use. MT-II is not on the WADA Prohibited List 2026. Artemis Labs does NOT market Melanotan-II as a tanning agent, cosmetic, sexual-enhancement product, or self-administered preparation. Research-use-only framing applies to all Artemis Labs commercial supply. These statements have not been evaluated by the FDA. Not for human consumption, therapeutic use, or veterinary use.

Science & Research

Mechanism of Action – Non-Selective Melanocortin Agonism

Melanotan-II is an alpha-MSH-derived cyclic heptapeptide that activates the melanocortin G-protein-coupled receptors MC1R, MC3R, MC4R, and MC5R non-selectively. MC1R activation on melanocytes drives eumelanin synthesis; MC3R/MC4R activation occurs across CNS reward and arousal circuitry; MC5R is expressed across exocrine and immune tissues. The non-selective receptor profile distinguishes MT-II from the MC3R/MC4R-selective bremelanotide (PT-141) and from the linear afamelanotide.

2025-2026 Research Refinements

• Adverse-event documentation – Resnick et al. 2026 (PMID 41890775; in J Clin Aesthet Dermatol): tanning-biology review explicitly documents unregulated Melanotan I/II adverse events including rhabdomyolysis, renal infarction, and priapism.
• Persistent gingival pigmentation – Bonchev 2026 (PMID 41752902; in Life (Basel)): case report of brown maxillary and mandibular gingival pigmentation following self-administered MT-II injections; mucosal pigmentation persisted at least 3 months after discontinuation.
• Public-health and dermatology signal – Sidhu et al. 2026 (PMID 41559011; in Int J Dermatol): social-media-driven unregulated melanotan use linked to ‘looksmaxxing’ culture and body-dysmorphic-disorder overlap.
• alpha-MSH-class stability landscape – Chawathe & Sharma 2026 (PMID 41547183; in J Pharm Biomed Anal): LC-HRMS framework mapping 14 distinct degradation products of afamelanotide under acidic, basic, neutral, oxidative, UV, and thermal stress. Cited as alpha-MSH-class analytical context relevant to MT-II purity verification.
• Sustained-release alpha-MSH-class delivery – Anderson et al. 2026 (PMID 41999898; in J Control Release): stereocomplexed beta-strand/hairpin hydrogel platform releasing alpha-MSH-analog peptide over months. Class-level PK innovation, cited as alpha-MSH-class context only.
• Afamelanotide-class context – Seidl-Philipp et al. 2026 (PMID 41793078; Austrian EPP real-world QoL data) + Barman-Aksoezen et al. 2026 (PMID 41885813; emerging EPP pharmacotherapies review) + Peshin et al. 2026 (PMID 41718315; CEP case) + Minder & Barman-Aksoezen 2025 (PMID 41542313; first pediatric afamelanotide case) – these are afamelanotide findings, cited here as alpha-MSH-class context only. They do NOT transfer to MT-II positioning.
• EPP combination context – Shetty et al. 2026 (PMID 41766687; in Photochem Photobiol): Polypodium leucotomos extract adjunct to afamelanotide implants in EPP. Afamelanotide-class context only.

Entity Disambiguation

Quality and Specifications

• Purity: ≥99% by RP-HPLC; identity confirmed by mass spectrometry
• Form: Lyophilised white powder, 10 mg/vial
• Storage: Lyophilised ≤ -20°C, desiccated, protected from light; if reconstituted, store at 2-8°C
• Documentation: Batch-specific Certificate of Analysis with HPLC chromatogram, MS identity, residual-solvent assay, and endotoxin testing available on request

Honest Limitations

• Documented adverse-event signal from unregulated use – rhabdomyolysis, renal infarction, priapism, persistent gingival pigmentation, social-media-driven misuse (Resnick 2026, Bonchev 2026, Sidhu 2026).
• Not FDA-approved in any formulation – several U.S. state Boards of Pharmacy have issued compounding advisories.
• Mechanistically related to but distinct from afamelanotide / Scenesse® – afamelanotide clinical findings do not transfer to MT-II positioning.
• Non-selective receptor profile creates broader systemic effects than the MC3R/MC4R-selective bremelanotide (PT-141).
• NOT a tanning agent, cosmetic, or self-administered preparation – Artemis Labs supplies MT-II strictly as a research reference compound.

References (10 PubMed-Verified, Scout 3 2026-05-20)

1. Minder AE, Barman-Aksoezen J (2025). JAAD Case Reports. PMID 41542313
2. Chawathe A, Sharma N (2026). J Pharm Biomed Anal. PMID 41547183
3. Sidhu AS et al. (2026). Int J Dermatol. PMID 41559011
4. Peshin S et al. (2026). Reports (MDPI). PMID 41718315
5. Bonchev A (2026). Life (Basel). PMID 41752902
6. Shetty N et al. (2026). Photochem Photobiol. PMID 41766687
7. Seidl-Philipp M et al. (2026). J Dtsch Dermatol Ges. PMID 41793078
8. Barman-Aksoezen J et al. (2026). Expert Opin Pharmacother. PMID 41885813
9. Resnick G et al. (2026). J Clin Aesthet Dermatol. PMID 41890775
10. Anderson CF, Wang X, Schneider JP (2026). J Control Release. PMID 41999898

Research Stacks

Stacking rationale below is mechanistic only. No dosing, frequency, duration, or protocol guidance is provided. Researchers design protocols against their own institutional review, not against vendor copy. Artemis Labs does NOT market Melanotan-II for combined use as a tanning, cosmetic, or self-administered regimen.

MT-II × PT-141

Receptor-selectivity comparison only: MT-II is non-selective across MC1R-MC5R; PT-141 is MC3R/MC4R-selective. Useful research-model pairing for dissecting selective vs broad melanocortin agonism within the same alpha-MSH-derived compound family. Not an Artemis stack-protocol.

MT-II × Oxytocin

Orthogonal receptor systems: MT-II acts across MC1R-MC5R; oxytocin acts on OXTR. Both are CNS-acting peptides studied within neuropeptide research contexts but on different receptor families. Useful research-model pairing for dissecting melanocortin-axis vs OXTR effects.

MT-II × Semax

The 2024 Inozemtseva et al. (PMID 39442746) paper directly compared MT-II vs Semax antidepressant/antistress effects in chronic stress models – a mechanism-comparator citation. Useful research-model pairing within the broader alpha-MSH / ACTH-derived neuropeptide family.

MT-II × VIP

Vasoactive-intestinal-peptide × non-selective melanocortin-agonist pairing studied in autonomic and vascular research models. Different receptor systems with convergent neuromodulatory effects across published research designs.

Related Compounds in Catalogue

For melanocortin-family research see PT-141. For OXTR-axis research see Oxytocin. For autonomic / vascular research counterparts see VIP. For ACTH-derived neuropeptide research see Semax and Selank.