Overview
Melanotan II (MT-II) is a synthetic cyclic heptapeptide analog of alpha-melanocyte-stimulating hormone (α-MSH), developed at the University of Arizona in the 1980s–1990s. It contains a D-phenylalanine substitution and a cyclizing lactam bridge that confers enzyme resistance and increases potency versus linear analogs. MT-II acts as a non-selective agonist at melanocortin receptors MC1R through MC5R, with notable activity at MC1R (pigmentation), MC3R (energy balance), MC4R (sexual function and appetite), and MC5R (exocrine glands).
PT-141 (bremelanotide) was derived from MT-II by removing the C-terminal amide to reduce melanogenic activity while retaining MC4R/MC3R activity. This lineage illustrates MT-II's central role in melanocortin peptide research. The broad receptor profile makes MT-II a versatile but complex research tool with multiple interacting pharmacological mechanisms.
Mechanism of Action
- MC1R agonism on melanocytes stimulating eumelanin production and skin darkening
- MC4R agonism in hypothalamus reducing food intake and increasing sexual arousal in rodent models
- MC3R agonism involved in energy homeostasis and anti-inflammatory signaling
- Melanin-independent photoprotective effects via upregulation of DNA repair mechanisms in keratinocytes
- MC5R agonism studied in exocrine gland secretion models
Specifications
| Full Name | Melanotan II (MT-II) |
| Sequence | Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-NH₂ |
| Formula | C₅₀H₆₉N₁₅O₉ |
| MW | 1,024.2 Da |
| CAS | 121062-08-6 |
| Purity | ≥98% HPLC |
| Form | Lyophilized powder |
| Appearance | White to off-white powder |
| Storage (lyophilized) | −20°C protected from light |
| Storage (reconstituted) | 2–8°C, 4–6 weeks |
| Solubility | Sterile water or dilute acetic acid |
Reconstitution
Reconstitute with sterile water or 0.6% acetic acid. Gently swirl. Store reconstituted at 2–8°C in amber or foil-wrapped vials within 4–6 weeks. Protect from light.
Quality & Purity
Every batch undergoes third-party HPLC testing to verify ≥98% purity. COA included with every order.
Research Use Only. Melanotan II is strictly for in vitro and laboratory research purposes. Not for human consumption, clinical use, or veterinary use. For use by qualified researchers only. These statements have not been evaluated by the FDA.