Synthetic Alpha-MSH Analog | CAS: 121062-08-6
Overview
Melanotan II (MT-2) is a synthetic cyclic heptapeptide analog of alpha-melanocyte-stimulating hormone (α-MSH). It was originally developed at the University of Arizona in the 1990s by Dr. Victor Hruby and Dr. Mac Hadley for research into melanocortin receptor activity and UV-independent tanning.
MT-2 is a non-selective agonist of melanocortin receptors MC1R through MC5R, making it one of the most versatile research tools for studying the melanocortin system. Its cyclic structure provides enhanced stability and receptor affinity compared to linear α-MSH analogs.
Mechanism of Action
MT-2 binds to and activates all five melanocortin receptor subtypes with varying affinities:
- MC1R activation: Triggers melanogenesis — the conversion of pheomelanin to eumelanin in melanocytes. Eumelanin provides darker pigmentation and offers greater photoprotection than pheomelanin. Research shows MT-2-induced pigmentation occurs even without UV exposure (Dorr et al., 1996).
- MC3R / MC4R activation: These receptors are highly expressed in the hypothalamus. MC4R activation modulates energy homeostasis, appetite regulation, and erectile function. MC3R plays a role in energy partitioning between lean and fat mass.
- MC5R activation: Primarily involved in sebaceous gland regulation and exocrine gland secretion.
- MC2R: MT-2 shows minimal activity at MC2R (ACTH receptor), which is relevant for its selectivity profile.
Pharmacokinetics
- Half-life: Approximately 1-2 hours following subcutaneous administration in research models.
- Bioavailability: High subcutaneous bioavailability due to cyclic structure resisting enzymatic degradation.
- Onset: Pigmentation changes observed within 5-7 days in preclinical models; peak effects at 3-4 weeks.
- Metabolism: Primarily hepatic degradation via peptidases.
Published Research
- Dorr et al. (1996) — Life Sciences: First demonstration of significant skin pigmentation increases with minimal UV exposure in human subjects. Showed dose-dependent melanogenesis.
- Wessells et al. (2000) — Journal of Urology: MC4R-mediated effects on erectile function. Demonstrated penile erection in 17 of 20 subjects.
- Hadley & Dorr (2006) — Peptides: Comprehensive 10-year review of MT-2 melanocortin receptor pharmacology.
- Hruby et al. (1995) — Journal of Medicinal Chemistry: Original structure-activity relationship studies defining cyclic peptide design.
- Ugwu et al. (1997) — Pharmaceutical Research: Stability and formulation studies of lyophilized MT-2.
- Barnetson et al. (2006) — Journal of Investigative Dermatology: MT-2 in combination with UV showed significant increase in melanin density and reduced sunburn cells.
- Dorr et al. (2004) — Archives of Dermatological Research: Phase I safety data demonstrating dose-dependent tanning response.
Research Applications
- Melanocortin receptor signaling pathway studies
- UV photoprotection research
- Appetite and energy homeostasis investigation
- Sexual function and MC4R pathway research
- Pigmentary disorder modeling
Chemical Properties
- Sequence: Ac-Nle-c[Asp-His-D-Phe-Arg-Trp-Lys]-NH2
- Molecular Weight: 1024.18 g/mol
- Molecular Formula: C50H69N15O9
- CAS Number: 121062-08-6
- Appearance: White to off-white lyophilized powder
- Solubility: Soluble in sterile water, bacteriostatic water, or 0.9% saline
- Storage: -20°C for long-term; 2-8°C reconstituted (up to 30 days)
Related product: Melanotan II (MT-2) — Janoshik-tested, COA included, research use only.
Disclaimer: This information is compiled from published peer-reviewed research for educational purposes only. Grey Research compounds are intended for in vitro research and laboratory use only. Not for human consumption.
Certificate of Analysis
Independent third-party HPLC lab test by Janoshik Analytical. Every batch is tested before release.
Click to view full-size lab report.