Synthetic cyclic melanocortin receptor agonist

Melanotan II

A cyclic α-MSH analogue studied for melanocortin-receptor pharmacology, pigmentation biology, and related neuroendocrine effects.

Also referred to as: Melanotan-2, MT-II, MT2, Ac-Nle-c[Asp-His-D-Phe-Arg-Trp-Lys]-NH2
Research use only. This page summarizes published scientific literature. It is not medical advice, not a recommendation, and not a claim that this compound treats, cures or prevents any condition. Nothing here is a suggestion to use it.

What Melanotan II is

Melanotan II is a synthetic cyclic heptapeptide analogue of α-melanocyte-stimulating hormone. In research settings it is used to probe melanocortin receptors, especially MC1R-linked pigmentation pathways and central MC3R/MC4R circuits involved in sexual function and energy balance. It is investigational and is discussed here strictly as a research compound.

Small human pilot studies in the 1990s characterized subcutaneous dosing, pigmentation changes, and dose-limiting effects such as nausea and yawning/stretching complexes. Separate controlled work examined erectile responses in men with psychogenic erectile dysfunction. Those papers are historical clinical-research documents, not modern use guides.

Because Melanotan II sits in a compliance-sensitive category often misused in cosmetic tanning communities, educational content must stay inside research-use-only language. No cosmetic self-administration guidance is provided or implied.

How it works

Melanotan II is a non-selective melanocortin receptor agonist. MC1R activation on melanocytes increases eumelanin synthesis, which is why pigmentation endpoints appear in early trials. Central MC3R/MC4R engagement helps explain observed effects on sexual behavior and appetite-related readouts in experimental models. Cyclic structure improves potency and enzymatic stability versus linear native α-MSH fragments.

Who works with it, and what they are measuring

Dermatology-adjacent pigment labs, melanocortin neuropharmacology groups, and sexual-medicine research units are the historical audiences. Regulatory, toxicology, and analytical chemists also study it because unregulated cosmetic channels created public-health surveillance questions. This profile is for research literacy only.

What the research examines

melanocortin receptor pharmacologypigmentation biologysexual function neuroendocrine researchenergy balance and appetite modelspeptide PK assay development

These describe where the compound shows up in published work. None of them should be read as an established outcome.

How it appears in the literature

Amounts reported in published research, shown for reference. Not a protocol.

Research contextReported amountFrequencyRoute
Pilot phase I subcutaneous research (Dorr et al.)700 mcg – 2.1 mgweekday research dosing over short coursessubcutaneous
Psychogenic ED pharmacodynamic study (Wessells et al.)1.75 mginvestigational single/short-term SC dosingsubcutaneous
See the full Melanotan II dosage chart, reconstitution math and calculator →

Handling & storage

Store lyophilized Melanotan II frozen or refrigerated per COA, dry and light-protected. After bacteriostatic-water reconstitution, keep refrigerated and protected from light; discard according to lab stability policy.

Notes on combined research

Research literature more often studies Melanotan II alone as a melanocortin probe than as part of a modern peptide stack. Mechanistic comparisons are made with afamelanotide/Melanotan I (linear NDP-MSH) and with selective MC4R agonists used in metabolic or sexual-function research. No cosmetic stacking discussion is appropriate or provided.

Melanotan II questions

Human pilot research commonly referenced about 0.025 mg/kg subcutaneously (on the order of 1–2 mg for many adult body weights) under clinical supervision. Those are historical trial exposures for research characterization only.

For a typical 10 mg research vial, 2–3 mL bacteriostatic water is a common laboratory dilution so that mcg/kg calculations are syringe-measurable. Exact volume is protocol-dependent.

Early phase I designs used repeated weekday subcutaneous doses over about two weeks rather than an indefinite daily lifestyle schedule. Published human work is short-course and supervised.

Research charts, when used, convert mg/kg trial doses into mcg for a stated body mass and diluent volume. They are literature translation tools, not tanning guides.

Rodent pharmacokinetic reports describe rapid plasma clearance, while pigmentation biology can continue after the peptide is no longer measurable in blood. Human half-life characterization remains limited compared with approved melanocortin drugs.

Controlled research generally evaluates it as a single melanocortin agonist. Combining research chemicals for cosmetic tanning is outside the scope of legitimate RUO education and is not advised here.

No. Afamelanotide (Melanotan I / NDP-MSH) is a related but distinct linear analogue with a different clinical development path. Melanotan II is the cyclic heptapeptide MT-II.

It is not an FDA-approved tanning or sexual-function drug, and unsupervised cosmetic use has raised safety and quality concerns. Educational content therefore stays inside research-literature framing.

Read the research yourself

Verified against PubMed, one by one. A reference you cannot open is not evidence.

Reference information only. The values below summarize amounts reported in published research literature and laboratory protocol discussions. They are not dosing recommendations, not medical advice, and not instructions for use in humans. All compounds referenced are for laboratory research use only and are not for human consumption.