Melanocortin Receptor
A melanocortin receptor is a protein on the surface of cells that receives signals from melanocortin hormones. Humans have five types, named MC1R through MC5R.
Where the word comes from
“Melano-” comes from the Greek melas, “black or dark” — the same root as melanin, the dark pigment. “-cortin” comes from the Latin cortex, “bark or rind,” through the “cortico-” naming of adrenal-cortex hormones. The melanocortin family is named for two of its jobs: dark-pigment signaling and adrenal-cortex signaling. “Receptor” is from the Latin recipere, “to receive.” The five human subtypes were identified and numbered MC1R through MC5R in the 1990s.
What it means here
Melanocortin receptors sit in several signaling pathways that published research maps in detail, including skin-pigment signaling, appetite signaling, sexual-arousal circuitry, and inflammation signaling. Compounds in our catalog such as PT-141 and Melanotan 2 are studied for how they bind and activate these receptors. Which receptor subtype a compound favors — MC1R versus MC4R, for example — is a central question in that research, because each subtype belongs to a different pathway.
Words you’ll see together
- MC1R … MC5R — the subtype names, numbered one through five
- alpha-MSH — the body’s natural melanocortin messenger peptide
- binding affinity — how tightly a compound holds on to a receptor
- nanomolar (nM) — the concentration unit binding affinity is usually reported in
Related terms
- Receptor — the general concept this entry is a specific case of
- Agonist — a compound that activates a receptor when it binds
- Peptide — the molecule class of the natural melanocortin messengers
Where it appears in our catalog
- PT-141 — studied as a melanocortin-receptor agonist across several subtypes
- Melanotan 2 — studied for binding at MC1R and other melanocortin receptors
- KPV — a short fragment of alpha-MSH, the body’s natural melanocortin messenger
References
- Bardhan M et al. (2025). MC1R/MC3R/MC4R polymorphisms modulate bremelanotide response variability. Diseases. PMID: 41002740
- Borland JM et al. (2025). Female Syrian hamster mapping bremelanotide effects on melanocortin-receptor-mediated sexual-reward circuitry. Neuropharmacology. PMID: 39793696
