Function
While PEG-MGF is used experimentally to enhance muscle repair and hypertrophy after mechanical overload or injury by stimulating satellite-cell activation and protein synthesis6373138, Tirzepatide is approved for type 2 diabetes and obesity, producing larger HbA1c and body-weight reductions than semaglutide in head-to-head trials24.
Mechanism
While PEG-MGF works as a poly(ethylene glycol)-conjugated form of Mechano Growth Factor (IGF-1Ec splice variant) comprising the 24-aa C-terminal E-peptide of IGF-1, designed to extend half-life while activating IGF-1 receptor–mediated anabolic signaling in muscle satellite cells637322138, Tirzepatide is a 39-amino-acid synthetic peptide primarily based on GIP sequence with C20 fatty diacid conjugation that acts as a dual agonist at GIP and GLP-1 receptors, enhancing glucose-dependent insulin secretion, suppressing glucagon, delaying gastric emptying, and reducing appetite24.