Gamma-MSH

Where it comes from

Made in

Pituitary corticotrophs, hypothalamic POMC neurons, and the intermediate lobe

Sent out by

With ACTH; in rodents, a high-salt diet raises it

Acts on

• Kidney and sympathetic nerves (sodium balance)
• Adrenal cortex (growth)
• Hypothalamus (energy balance)

What it does

• Makes rats shed sodium on a salty diet; without MC3R their blood pressure climbs with salt ²
• Helps the adrenal grow and respond to ACTH
• MC3R also sets the timing of puberty and the rate of growth in people ¹

In medicine

• None of its own, and no assay in routine use; the melanocortin medicines act on MC1R and MC4R rather than MC3R
• People carrying loss-of-function MC3R variants enter puberty later and are shorter and leaner in childhood, with lower IGF-1 ¹

Beyond the body’s own use

• No gamma-MSH product exists and none is in trial; the interest has moved to its receptor
• The salt-handling story is a rodent one: mice without MC3R become salt-sensitive and hypertensive, and nothing equivalent has been shown in people ²
• The human finding that holds is about growth and puberty, and it suggests MC3R decides where calories go while MC4R decides how many are taken in ¹
• MC3R-selective agonists and antagonists exist as laboratory tools only, and no clinical use has been proposed for them