Melanotan II is a synthetic cyclic heptapeptide analogue of alpha-melanocyte-stimulating hormone (alpha-MSH) that non-selectively activates melanocortin receptors MC1R through MC5R. Originally developed for photoprotective skin tanning, it also affects sexual function (MC3R/MC4R) and appetite (MC4R). PT-141 (bremelanotide) was derived from MT-II research as its active metabolite responsible for sexual arousal effects. MT-II is not approved for human use in any country, and multiple regulatory agencies have issued explicit safety warnings against its use.
32 vendors tracked by PeptideAtlas list Melanotan II, priced from $24.00 to $150. The lowest price per milligram is $2.40/mg at Legendary Peptides (10mg). 9 independent Janoshik purity tests cover Melanotan II across 6 vendors. Results range from 99.7% to 99.9%.
Category: Melanocortin Agonist. Evidence rating: F (anecdotal/unsupported).
Clinical status: Research-only / Not approved. Multiple regulatory warnings issued worldwide.
MT-II activates melanocortin receptors MC1R through MC5R non-selectively. MC1R activation stimulates melanogenesis (skin tanning) in melanocytes. MC3R/MC4R activation in the CNS increases sexual arousal and desire via dopamine release pathways. MC4R activation centrally suppresses appetite. The…
Research base: 1 registered clinical trial and 11 indexed publications reference Melanotan II.
Safety considerations: Nausea (very common, especially at initial doses); Facial flushing and warmth; Spontaneous erections (in males).
Reviewed by the PeptideAtlas Editorial Team.
| Amino-acid sequence | Ac-Nle-Asp-His-D-Phe-Arg-Trp-Lys-NH2 |
|---|---|
| Molecular weight | ~1024.2 g/mol |
| CAS number | 121062-08-6 |
| Half-life | ~36 minutes IV; longer SC due to depot effect |
| Production method | synthetic |
| Anti-doping status | Prohibited in sport (WADA) |
| US regulatory status | Not FDA-approved. FDA has issued warnings against use. Removed from Category 2 on April 15, 2026. PCAC review scheduled July 23-24, 2026 to determine compounding eligibility. |
| Vendor | Size | Price | Price per mg |
|---|---|---|---|
| Legendary Peptides | 10mg | $24.00 | $2.40/mg |
| Wholesale Peptide | 10mg | $25.49 | $2.55/mg |
| Evolve BioPep | 10mg | $28.00 | $2.80/mg |
| PureRx Peptides | 10mg | $28.00 | $2.80/mg |
| Athena Peptides | 10MG | $29.00 | $2.90/mg |
| Mammoth Muscle Peptides | 10MG | $30.00 | $3.00/mg |
| Sentinel Valor | 10MG | $30.00 | $3.00/mg |
| Lux Synth Aminos | 10mg | $35.00 | $3.50/mg |
| Peak Peptides | 10mg | $35.00 | $3.50/mg |
| Arcane Peptides | 10mg | $35.00 | $3.50/mg |
| Choice Peps | 10mg | $38.00 | $3.80/mg |
| Axon Chems | 10mg | $40.00 | $4.00/mg |
| Protide Health | 10mg | $40.00 | $4.00/mg |
| BioTech Peptides | 10mg | $41.00 | $4.10/mg |
| Particle Peptides | 10mg | $41.00 | $4.10/mg |
| Compound Purity | 10mg | $43.00 | $4.30/mg |
| Ameano Peptides | 10mg | $44.00 | $4.40/mg |
| Pepix Labs | 10MG | $45.00 | $4.50/mg |
| Honest Peptide | 10mg | $45.00 | $4.50/mg |
| Red Fox Peptides | 10 mg | $45.00 | $4.50/mg |
| Lab Trust Peptides | 10mg | $49.99 | $5.00/mg |
| Peplogix Peptides | 10mg | $50.00 | $5.00/mg |
| Lucky Link Peptides | 10MG | $50.00 | $5.00/mg |
| Growth Guys | 10mg | $50.00 | $5.00/mg |
| Great Northern Peptides | 10mg | $50.00 | $5.00/mg |
| Vendor | Best tested purity |
|---|---|
| HPR | 99.9% |
| Panda Peptides LLC | 99.9% |
| MOB Peptides | 99.8% |
| Peptide Gurus | 99.8% |
| Peptide Crafters | 99.8% |
| Imperial Peptides | 99.7% |
Related peptides: Afamelanotide.
Multiple regulatory agencies worldwide have warned against its use. It is not approved for human use in any country. Risks include interference with melanoma detection, unpredictable mole changes, and unknown long-term effects on skin cancer risk.
No. Melanotan I (afamelanotide/Scenesse) is more selective for MC1R and is EMA-approved for erythropoietic protoporphyria (EPP). Melanotan II is non-selective across MC1R-MC5R and not approved for any use.
Yes. PT-141 (bremelanotide) is the active metabolite of Melanotan II that was isolated for its sexual arousal effects. It received FDA approval (Vyleesi) for female HSDD in 2019, while MT-II itself remains unapproved.
The long-term effects on melanocyte transformation are unknown. MT-II stimulates melanocyte activity and can cause new or changing moles, which complicates melanoma screening. This is a primary safety concern cited by regulatory agencies.
Yes. WADA prohibits all peptide hormones and growth factors not approved for human therapeutic use, which includes Melanotan II.
Vendors with independent lab tests for it: HPR, MOB Peptides.
Vendors stocking it: Direct Peptides UK, BioTech Peptides, LimitlessBioChem, Polar Peptides, Risynth Bio, Lux Synth Aminos, M-Peptides, Amino Lair, Zztai Peptide, Evolve BioPep, Wolverine Peptides, Pepix Labs, Biomax Research, NovaPeptide, Ultima Pharmaceuticals, Ameano Peptides, Prime Lab Peptides, Pacific Peptide, Mammoth Muscle Peptides, Axon Chems, Lab Rat Peptide, Ascension Peptides, Choice Peps, Wholesale Peptide, BleauGenics, Compound Purity, Purus Peptides, Peplogix Peptides, Petratide Science, SupraChems, Legendary Peptides, Lab Trust Peptides, Supopeptide, Treasure Coast Peptides, BioPure Peptides, US Chem Labs, Burly Labs, Athena Peptides, PureRx Peptides, Catalyst Peptides.
Coverage on this site: Imperial Peptides UK sets MT-2 documentation standard for research supply, MT-2 Peptide Research: Melanocortin and Pigmentation in Canada, Retatrutide Monthly Research Cost in Australia Breakdown, Melanotan 2 Explained: Origins, Tanning Science, and Key Benefits, Melanotan 1: Tanning Peptide with Broad Research Potential, Premium Research Peptides for Australian Lab Studies.