MGF (Mechano Growth Factor)

MGF (Mechano Growth Factor) is a splice variant of insulin-like growth factor-1 (IGF-1) produced locally in skeletal muscle in response to mechanical stress, damage, or exercise. The MGF E-peptide domain differs from systemic IGF-1Ea, giving it unique local autocrine/paracrine functions. Research demonstrates MGF specifically activates muscle satellite cells—the resident stem cells responsible for muscle fiber repair and growth—initiating their proliferation before they differentiate into mature myocytes. This sequential process is critical for effective muscle regeneration. Studies show MGF expression peaks shortly after exercise or injury, preceding IGF-1Ea upregulation. The peptide may enhance muscle hypertrophy, accelerate recovery from exercise, and support tissue repair. PEG-MGF is a pegylated variant with extended half-life allowing systemic effects. Research continues into applications for sarcopenia, muscle wasting diseases, and injury recovery. MGF represents the local muscle tissue's immediate response to mechanical signals, distinct from liver-derived circulating IGF-1.

MGF is an endogenous splice variant, not an approved drug. Exogenous MGF peptide use has no clinical trial support; human data are limited to expression measurements in muscle biopsies. Half-life and dosing claims for MGF/PEG-MGF are not established in reliable published sources.

MGF is the IGF-1Ec splice variant expressed locally in skeletal muscle after mechanical loading; the E-peptide domain activates muscle progenitor cells in culture. As a research peptide it is administered by injection, with pegylated (PEG-MGF) forms proposed to extend duration — neither has published human pharmacokinetic characterization.