POMC → MC1R–MC5R · the melanocortin axis

Five receptors. One ancient signalling system. The most underrated axis in medicine.

It sets your skin's colour, tunes your stress response, gates your hunger, and calms a healing wound — yet most people have never heard its name. The melanocortin axis spent a century as a lab curiosity before becoming one of pharma's hottest frontiers. This is the field guide to the whole system and the drugs now built on it — every claim cited, nothing oversold.

Start with the system See what's in the clinic

MC1RSkin & hair pigmentation MC2RAdrenal cortisol (the ACTH receptor)MC3REnergy balance & inflammation MC4RAppetite & body weight MC5RExocrine gland function

Why now

A biological curiosity just became a drug class.

The melanocortin system was mapped long before anyone could drug it well. That changed fast. The same economy that makes it elegant — one gene, reused across organs — makes it a rare thing in pharmacology: a single family of targets that reaches obesity, pigment disease, inflammation, pain, and sexual function at once.

One generuns the whole systemPOMC is cut, tissue by tissue, into the peptides that set pigment, the stress axis, appetite, and inflammation — read by five receptors, held in check by two natural brakes.

3 in 24 monthsfirst-in-class approvalsFor decades, no drug was designed to hit a melanocortin receptor. Between 2019 and 2020, three did — for a pigment disorder, sexual dysfunction, and genetic obesity.

~12 agentsnow in the clinicThe pipeline is going oral and broad: obesity, dry eye, ulcerative colitis, cancer cachexia — and the first oral MC4R and MC1R drugs are moving through trials.

That is the wager this site is built on: melanocortin pharmacology is early, and early is exactly when a clear, honest map is worth the most. The live pipeline tracks every agent through the clinic, dated and sourced.

Three ways in

Broad overviews that link down into specific, citeable detail — the system, the five receptors, and the drugs built on them.

Start hereThe melanocortin systemHow one precursor — POMC — becomes the peptides that signal across pigmentation, the stress axis, appetite, and inflammation. The whole map in one page.Read →Five switchesMC1R through MC5RA page for each receptor: where it lives, what binds it, what it controls, and what breaks when it fails. The five levers the whole field is built on.Read →The frontierTherapeutics & the pipelineApproved and investigational melanocortin drugs — from setmelanotide and afamelanotide to the oral and anti-inflammatory agents opening the field wide.Read →

Reverent on the science. Sceptical on the page.

Reverence only counts if it survives the citations. Every page carries a visible author and a last-updated date. Therapeutic and pipeline claims are checked against current sources before publication, and where the science is uncertain or contested, the page says so — rather than papering over it. When the frontier is genuinely unsettled, we call it the frontier, not a sure thing.

This is an educational resource, not medical advice. Read the editorial standards →