Introduction
Melanocortin peptides are a family of endogenous and synthetic peptides that act on a family of five G protein-coupled receptors (MC1R–MC5R). Originally studied in the context of pigmentation and adrenal function, melanocortin research has expanded significantly to encompass inflammation, immune modulation, sexual function, appetite regulation, and neuroprotection.
For research and laboratory use only. Not intended for human or veterinary administration.
The Melanocortin System
Melanocortin peptides are derived from the precursor protein proopiomelanocortin (POMC), which is cleaved to produce α-MSH, β-MSH, γ-MSH, ACTH, and β-endorphin. Each melanocortin receptor subtype has a distinct tissue distribution and functional profile:
- MC1R: Expressed on melanocytes — primary regulator of skin and hair pigmentation. Also expressed on immune cells.
- MC2R: Expressed in the adrenal cortex — the ACTH receptor, regulating cortisol synthesis.
- MC3R: Expressed in the hypothalamus and limbic system — involved in energy homeostasis and inflammation.
- MC4R: Expressed widely in the CNS — key regulator of appetite, energy expenditure, and sexual function.
- MC5R: Expressed in exocrine glands — involved in sebaceous gland function and immune modulation.
Key Research Compounds
α-MSH (Alpha-Melanocyte-Stimulating Hormone)
The endogenous tridecapeptide agonist at MC1R, MC3R, MC4R, and MC5R. α-MSH has been extensively studied for its anti-inflammatory properties — it inhibits NF-κB signalling and downregulates pro-inflammatory cytokines including TNF-α, IL-1β, and IL-6. Research applications include inflammation models, neuroprotection, and pigmentation biology.
Melanotan I (Afamelanotide)
A linear analogue of α-MSH with enhanced MC1R selectivity and extended half-life compared to native α-MSH. Melanotan I has been studied primarily in the context of photoprotection and pigmentation research, with MC1R activation stimulating eumelanin production in melanocytes. Research has also explored its anti-inflammatory properties via MC1R on immune cells.
Melanotan II
A cyclic analogue of α-MSH with broader receptor activity, acting as an agonist at MC1R, MC3R, MC4R, and MC5R. The broader receptor profile compared to Melanotan I makes it a valuable research tool for investigating multiple melanocortin pathways simultaneously. Research applications include pigmentation biology, appetite regulation (MC3R/MC4R), sexual function (MC4R), and inflammation models.
PT-141 (Bremelanotide)
A cyclic heptapeptide derived from Melanotan II, with primary activity at MC4R. PT-141 has been studied extensively in models of sexual function, where MC4R activation in the CNS mediates pro-erectile and pro-sexual effects through a mechanism distinct from PDE5 inhibitors. Research has also explored its role in MC1R-mediated inflammation.
KPV
A tripeptide (Lys-Pro-Val) representing the C-terminal active fragment of α-MSH. KPV retains significant anti-inflammatory activity through melanocortin receptors while offering a simpler molecular structure. Research applications include inflammatory bowel disease models, skin inflammation, and antimicrobial activity.
ACTH Analogues
ACTH(1-24) and related fragments are used in research models of adrenal function, cortisol regulation, and HPA axis biology. ACTH acts exclusively at MC2R in the adrenal cortex to stimulate steroidogenesis.
Research Applications
- Pigmentation biology and photoprotection models
- Inflammation and innate immune modulation research
- Appetite regulation and energy homeostasis models (MC3R/MC4R)
- Sexual function and MC4R pharmacology research
- HPA axis and adrenal function models
- Neuroprotection and neuroinflammation research
- Skin biology and sebaceous gland function
Storage and Handling
Store lyophilised melanocortin peptides at −20°C, protected from light. Melanotan II and PT-141 are particularly light-sensitive — use amber vials where possible and minimise light exposure after reconstitution. Reconstitute with bacteriostatic water. Once reconstituted, store at 2–8°C and use within 28 days.
All products supplied by Vanta Labs are intended strictly for laboratory and research purposes.