Melanotan II (MT2)

What is Melanotan II (MT2)?

Melanotan II (MT2) is a synthetic cyclic heptapeptide analogue of the endogenous 13-amino-acid hormone alpha-melanocyte-stimulating hormone (alpha-MSH). It was developed at the University of Arizona as a lactam-cyclised, enzymatically stable version of the alpha-MSH core sequence, with norleucine replacing methionine and D-phenylalanine replacing L-phenylalanine. GenoPept supplies melanotan II UK laboratories in 5mg and 10mg lyophilised research vials.

Unlike melanotan 1, which is a linear peptide selective for the MC1 receptor, melanotan II is a non-selective agonist at MC1, MC3, MC4 and MC5 receptors. This broad activity is why it has been investigated in both pigmentation and central nervous system research, and it is the parent compound from which PT-141 (bremelanotide) was derived.

Melanotan II (MT2) research applications

Melanotan II peptide is used in melanocortin receptor pharmacology, dermatological cell biology and behavioural neuroscience. The applications below summarise preclinical and in-vitro research and are not claims about effects in people.

Melanogenesis and MC1 receptor biology

In melanocyte cell-culture and animal models, melanotan II is used to stimulate MC1 receptor signalling and study eumelanin synthesis, tyrosinase expression and the cellular response to ultraviolet exposure.

Central melanocortin signalling

Melanotan II is a standard tool for activating MC3 and MC4 receptors in the hypothalamus of animal models, where researchers investigate feeding behaviour, energy expenditure and autonomic regulation.

Behavioural neuroscience

Animal studies have investigated melanotan II in models of sexual behaviour and arousal, work that led directly to the development of PT-141 as a compound with less MC1-related activity.

Receptor selectivity and structure-activity research

Research explores how the lactam cyclisation, norleucine and D-phenylalanine substitutions confer stability and affinity, using melanotan II as a reference against which selective melanocortin agonists and antagonists are compared.

Photoprotection and DNA-damage models

Cell-culture research has examined whether melanocortin agonists such as melanotan II influence DNA-repair pathways and oxidative stress responses in melanocytes exposed to ultraviolet radiation.

Mechanism of action (preclinical)

Melanotan II binds melanocortin receptors, a family of Gs-coupled G protein-coupled receptors, and increases intracellular cAMP through adenylyl cyclase. At the MC1 receptor on melanocytes this cAMP signal activates the microphthalmia-associated transcription factor (MITF), upregulating tyrosinase and shifting melanin synthesis towards eumelanin in preclinical models.

At MC3 and MC4 receptors in the central nervous system, melanotan II modulates hypothalamic circuits involved in appetite, energy balance and sexual behaviour in animal studies. The cyclic lactam structure protects the His-D-Phe-Arg-Trp pharmacophore from proteolysis, giving melanotan II far greater potency and duration than native alpha-MSH.

Melanotan II (MT2) product specifications

Available sizes

GenoPept offers melanotan II in two vial sizes for cell-culture assays and larger animal-model programmes:

• 5mg vial
• 10mg vial

Laboratories running larger studies can order it in bulk boxes of 10 vials at 20–50% below single-vial pricing through our bulk and wholesale page, with UK-only retail delivery.

Reconstitution, handling and storage (laboratory)

This compound is supplied as a lyophilised powder and should be stored unopened at –20 °C for long-term holding, or at 2–8 °C for short periods, always protected from light. Melanotan II contains tryptophan and histidine residues that oxidise readily, so protect the powder and any solutions from light and avoid repeated freeze-thaw cycles.

To reconstitute for in-vitro work, add bacteriostatic water or another sterile diluent slowly down the inside wall of the vial, then swirl gently until the powder dissolves. Never shake the vial, because shear can damage the molecule. After reconstitution keep the solution at 2–8 °C and use it within the period stated in the laboratory protocol. UK laboratories can also read our guides on how to reconstitute research peptides and how to store research peptides.

Quality assurance and Certificate of Analysis

Purity and identity results are batch-specific. Consult the applicable supplied report for its results and methods; confirm the batch covers current stock and verify the laboratory’s accreditation scope directly.

For melanotan II the LC-MS identity test confirms the mass of the amidated cyclic heptapeptide and distinguishes it from PT-141, which has a free acid terminus. Our article on what a Certificate of Analysis shows explains how to read the purity chromatogram and mass spectrum. Orders are dispatched from the UK by tracked Royal Mail Special Delivery (£10, free on orders of £200 or more), with automatic cart discounts of 5% from £300, 10% from £500 and 15% from £1,000. We accept card, Apple Pay, Google Pay and cryptocurrency payments.

Related research compounds

• Melanotan 1 (MT1) 10mg – the linear, MC1-selective alpha-MSH analogue for pigmentation-focused research.
• PT-141 (Bremelanotide) 10mg – the derivative of melanotan II studied for central MC3 and MC4 receptor signalling.
• GHK-Cu Copper Peptide – a complementary peptide for skin and dermatological cell-model research.
• Oxytocin – a neuropeptide often studied alongside melanocortins in behavioural neuroscience.

Melanotan II (MT2) frequently asked questions

What is melanotan II used for in research?

Melanotan II is used to study melanocortin receptor signalling in melanocyte cell cultures and animal models, including melanogenesis via the MC1 receptor and central MC3 and MC4 pathways involved in feeding, energy balance and sexual behaviour. It is also a reference agonist in structure-activity and receptor-selectivity research. All applications are preclinical or in-vitro.

How is melanotan II supplied and what purity is it?

Purity and identity results are batch-specific. Consult the applicable supplied report for its results and methods; confirm the batch covers current stock and verify the laboratory’s accreditation scope directly.

How should melanotan II be stored?

Keep unopened melanotan II vials at –20 °C for long-term storage, or at 2–8 °C for short periods, protected from light. After reconstitution with bacteriostatic water or sterile diluent, store the solution at 2–8 °C and use it within the timeframe your laboratory protocol specifies. Avoid repeated freeze-thaw cycles and never shake the vial.

Is melanotan II for human use?

No. Melanotan II from GenoPept is sold strictly for in-vitro laboratory research. It is not for human or veterinary use, it is not a medicine, and it is not for diagnostic or therapeutic purposes. We do not provide dosing or administration guidance, and nothing on this page should be read as medical advice.

What is the difference between melanotan II and melanotan 1?

Melanotan II is a cyclic heptapeptide that activates MC1, MC3, MC4 and MC5 receptors, so it is studied in both pigmentation and central nervous system models. Melanotan 1 (afamelanotide) is a linear 13-amino-acid alpha-MSH analogue that binds predominantly the MC1 receptor, making it the preferred tool for pigmentation and photoprotection research without significant central melanocortin activity.

Research use only. Melanotan II is supplied strictly for in-vitro laboratory research. It is not for human or veterinary use, it is not a medicine, and it is not for diagnostic or therapeutic use. Nothing on this page is medical advice. Read our research use only policy and guide to research peptides and UK law before ordering.