PEG-MGF (Mechano Growth Factor)
Wellness
In plain English
PEG-MGF is a lab-made version of a splice variant of IGF-1 that muscle produces after it is loaded or damaged; the "PEG" (polyethylene glycol) attachment is meant to make it last longer in the body. In theory it helps activate the muscle's repair cells (satellite cells). The supporting research is from cells and animals; there are no completed human trials of PEG-MGF for muscle growth or recovery, and it is not FDA-approved. It is sold as a research chemical.
The science
Mechano growth factor (MGF) is the IGF-1Ec splice variant generated locally in mechanically stressed or damaged muscle; its distinct E-domain C-terminal peptide is thought to activate satellite (muscle stem) cells before the mature IGF-1 signal drives differentiation. In cell studies the synthetic MGF E-peptide activated and increased proliferation of human muscle-derived progenitor cells (Kandalla et al., 2011), supporting a role in early repair. PEG-MGF is a pegylated preparation intended to extend a very short native half-life. Evidence is preclinical/mechanistic; there are no published human clinical trials of PEG-MGF, it is banned in sport (WADA), and it is not FDA-approved.
References
- Kandalla PK et al., Mech Ageing Dev 2011 (MGF E-peptide activates human muscle progenitors)
- Goldspink G, Curr Opin Pharmacol 2008 (review: growth factors, muscle, doping)