PEG-MGF
PEG-MGF is a pegylated, long-acting form of mechano growth factor (MGF) — the IGF-1Ec splice variant's C-terminal E-domain peptide — studied preclinically for satellite-cell activation and local skeletal-muscle repair; research protocols typically use 100-400 mcg (commonly ~200 mcg) subcutaneously on training days, post-workout. Note the dose is in MICROGRAMS (mcg), not milligrams — a 1000x difference.
It has been studied primarily in preclinical models for local skeletal-muscle repair, satellite (muscle stem) cell activation, and hypertrophy following mechanical overload or injury, with additional research interest in muscle-wasting and cardiac-tissue contexts. It is used strictly as a research compound and is not an approved therapy.
PEG-MGF (pegylated mechano growth factor) is a research-grade, pegylated analog of MGF, the IGF-1Ec splice variant produced by exercised or damaged skeletal muscle. Where the full IGF-1 gene can be alternatively spliced, MGF corresponds to the unique C-terminal E-domain peptide (a 24-amino-acid sequence in the human IGF-1Ec isoform) that is cleaved from the IGF-1 mature region. In muscle research MGF is characterized as an early, local response to mechanical overload: it is studied for activating and proliferating satellite (muscle stem) cells and delaying their differentiation, thereby expanding the pool available for repair and hypertrophy, with signaling reported to act through a mechanism partly distinct from the classic IGF-1 receptor pathway.
Native MGF is degraded within minutes; attaching polyethylene glycol (pegylation) is intended to protect the peptide from rapid proteolysis and extend its circulating half-life so a systemic injection can sustain exposure. None of this is FDA-approved; PEG-MGF is not a drug and is handled as a research compound, with most characterization coming from cell and animal studies rather than validated human trials.
Research literature on injectable PEG-MGF protocols is limited and not standardized; documented research dosing sits in the microgram range — commonly cited as roughly 100-400 mcg per administration (a frequently referenced starting point is ~200 mcg), given subcutaneously on training days shortly after exercise to coincide with the mechanical-loading repair window. The pegylation is intended to extend the very short native MGF half-life so less frequent dosing (e.g. a few times weekly rather than daily) is used. Reconstitute the 2 mg vial with 2 mL bacteriostatic water (1000 mcg/mL) and draw carefully — at 1000 mcg/mL, a 200 mcg dose is only 20 units on a U-100 insulin syringe.
No validated human time-to-effect has been established. Native MGF acts locally over hours-to-days after mechanical stress; pegylation extends systemic exposure, and any hypertrophy-related endpoints in animal research are characterized over multi-week study periods rather than acutely.
In research and anecdotal contexts it is sometimes discussed alongside growth-hormone secretagogues (e.g. GHRH/GHRP compounds) or standard IGF-1/GH-axis peptides, with the idea of pairing a systemic GH pulse with a local repair signal; controlled human stacking data are lacking.
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This page is educational reference material about compounds studied in research settings. It is not medical advice, and nothing here is a recommendation to buy, possess, or use any compound. Research findings described are from published literature; individual compounds may not be approved for human use. Talk to a licensed clinician about anything that affects your health.