ACE-031 vs Ghrelin

Soluble decoy receptor for ActRIIB; sequesters myostatin, activin, and GDF-11 to remove multiple brakes on muscle and bone growth simultaneously

A soluble decoy receptor that blocks the ActRIIB pathway, inhibiting myostatin and related TGF-β family proteins. Produces dramatic muscle and bone gains but carries cardiovascular risks at high doses.

Must be acylated at Ser3 (by GOAT enzyme) for GHSR-1a binding. Receptor activation in the pituitary stimulates GH release; hypothalamic action via NPY/AgRP neurons increases appetite and reduces energy expenditure.

An endogenous 28-amino acid peptide hormone produced primarily by gastric oxyntic cells. Functions as both the primary hunger signal and a potent GH secretagogue. The natural ligand for the growth hormone secretagogue receptor (GHSR-1a).