MGF
Also known as: Mechano Growth Factor, IGF-1Ec, PEG-MGF, MGF C-Terminal
A splice variant of IGF-1 that is produced when muscle tissue is stretched or damaged. Available as standard MGF (short-lived) and PEG-MGF (longer-lasting pegylated form). Used primarily in research for muscle repair, though scientific evidence for the isolated peptide fragment is mixed.
How it works
When your muscles are stretched or damaged during exercise, the IGF-1 gene gets spliced differently to produce MGF. MGF activates muscle satellite cells (stem cells), which are the repair crew for damaged muscle fibers. PEG-MGF has a polyethylene glycol chain attached that extends its half-life from minutes to 48-72 hours.
Common uses
- Muscle repair and recovery
- Muscle growth support
- Sports injury recovery
- Age-related muscle loss (sarcopenia research)
Side effects
- Very limited human safety data
- Injection site pain or irritation
- Possible localized swelling
- Potential blood sugar effects (related to IGF-1 pathway)
- Long-term effects unknown
Key research
- In vitro study showed MGF-E peptide activates human muscle progenitor cells and increases their fusion potential
- However, one study found MGF peptide alone had no apparent effect on myoblasts or primary muscle stem cells, calling its isolated role into question
- PEG-MGF shows enhanced stability and potentially stronger effects than unmodified MGF in animal models
Safety notes
- Not FDA-approved for any medical use
- Research results on the isolated MGF peptide are mixed. Some studies question whether it works on its own
- Banned by WADA for athletic competition
- Quality and purity of commercially available MGF vary widely
- Should only be used under medical supervision for research purposes
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