Melanocortin research peptides in Australia
The melanocortin range holds the three alpha-MSH analogues: Melanotan I (afamelanotide), selective for MC1R and registered in Australia only as the Scenesse implant; Melanotan II, cyclic and non-selective, with tanning, sexual-response and appetite effects; and PT-141 (bremelanotide), the Melanotan II metabolite developed for sexual-desire disorder. Melanotan is searched about 24,000 times a month in Australia, and the TGA has warned publicly about Melanotan II.
Compounds in this category
Melanotan I
Linear MC1R-selective alpha-MSH analogue
Melanotan I is a linear 13-amino-acid analogue of alpha-MSH with two substitutions that make it resistant to breakdown. It is selective for the MC1R receptor, so its activity is largely confined to pigmentation. Afamelanotide trials in erythropoietic protoporphyria reported more pain-free sun exposure and fewer phototoxic reactions; vitiligo studies reported faster repigmentation with phototherapy.
Melanotan II
Cyclic non-selective melanocortin receptor agonist
Melanotan II is a cyclic heptapeptide analogue of alpha-MSH developed at the University of Arizona in the 1980s. It activates several melanocortin receptors rather than only MC1R, which is why its research profile covers pigmentation, sexual function and appetite together. Early human studies documented tanning with minimal UV exposure over a few weeks, plus the erectile-response effect that led to PT-141.
PT-141
Cyclic melanocortin agonist (MC3R/MC4R) derived from Melanotan II
PT-141 is the deamidated metabolite of Melanotan II, developed after MT-II's sexual-response effect was noticed in early trials. It acts centrally through MC3R and MC4R rather than on blood flow, which distinguishes it from PDE5 inhibitors. RECONNECT Phase 3 trials reported increased sexual-desire scores and reduced distress versus placebo in premenopausal women; earlier studies in men reported erectile responses independent of nitric oxide.
Melanocortin Agonists at a glance
| Compound | Class | Formats | From | Studied for |
|---|---|---|---|---|
| Melanotan I | Linear MC1R-selective alpha-MSH analogue | 10mg | $79.99 | MC1R selectivity, Photoprotection |
| Melanotan II | Cyclic non-selective melanocortin receptor agonist | 10mg | $79.99 | Melanogenesis, Melanocortin pharmacology |
| PT-141 | Cyclic melanocortin agonist (MC3R/MC4R) derived from Melanotan II | 10mg | $99.99 | Central arousal pathways, Sexual-desire research |
Receptor selectivity is the whole story
All three are analogues of alpha-melanocyte-stimulating hormone. Melanotan I keeps the linear backbone and binds mainly MC1R on melanocytes, so its activity is confined to pigmentation and photoprotection, which is what the Scenesse trials in erythropoietic protoporphyria measured. Melanotan II is a cyclic heptapeptide with far higher potency and activity at MC3R and MC4R in the brain, which produces the sexual-response and appetite effects and the broader side-effect profile. PT-141 is Melanotan II's deamidated metabolite, keeping the central sexual-response effect; as bremelanotide it completed Phase 3 trials (RECONNECT) and is registered in the United States. The Melanotan 1 vs 2 guide compares them in detail.
Nasal sprays, kits and the vial
'melanotan nasal spray' and 'pt 141 nasal spray' together account for around 3,000 monthly searches, and none of those products is regulated or verified. Melanotan injection 'kits' bundle vials of unknown origin. Peptide Aus supplies all three compounds as 10mg lyophilised vials for research, reconstituted with 2 mL of bacteriostatic water, with a batch certificate available on request.
Side effects reported
Melanotan II: nausea, flushing, appetite loss, spontaneous erections and darkening of existing moles, with dermatologists and the TGA warning about changes in naevi. PT-141: nausea in around 40% of Phase 3 participants, flushing, headache, transient blood-pressure increases and skin darkening with repeated use. Melanotan I: nausea, headache and mole darkening in the afamelanotide trials. Each product page carries the full research summary.
Legal status in Australia
Afamelanotide is a prescription medicine only as the Scenesse implant. Melanotan II is unapproved, and the TGA has stated that supplying it for human use is illegal. Bremelanotide is not registered by the TGA. Research supply of all three is for in-vitro laboratory use, with the buyer responsible for lawful use; the Melanotan 2 in Australia guide covers the regulatory position.
Frequently asked questions
Melanotan 1 or 2?
Melanotan I is MC1R-selective and linear; Melanotan II is non-selective and cyclic, with sexual and appetite effects and a broader side-effect profile.
Is Melanotan 2 legal in Australia?
Supply for human use is illegal per the TGA. Research-grade material can be sold for laboratory use.
Do you sell Melanotan nasal spray?
No. Vials only. Sprays sold online carry no verified content.
What is PT-141?
Bremelanotide, the Melanotan II metabolite developed for sexual-desire disorder and registered in the US as Vyleesi.
Is Melanotan I the same as Scenesse?
Same peptide, different product: Scenesse is a registered implant, the vial is research powder.
Research use only: every product in this category is intended for in-vitro laboratory research. Not for human or veterinary use.