The IGF-1 splice variant produced by mechanically loaded muscle — MGF for post-workout local action, PEG-MGF for twice-weekly systemic dosing.
Mechano Growth Factor (MGF) is a splice variant of IGF-1 — specifically IGF-1Ec — produced locally by skeletal muscle in response to mechanical loading. Its distinct C-terminal E-domain triggers satellite-cell activation and muscle repair independently of the systemic IGF-1 axis.
Native MGF has a serum half-life of only minutes, which motivated the development of PEG-MGF — a polyethylene-glycol-conjugated version with a ~48–72 hour half-life, practical for twice-weekly systemic dosing.
Not FDA approved. WADA prohibited (S2). Research chemical only.
MGF’s E-domain activates quiescent satellite cells lining muscle fibers, driving their proliferation and fusion into existing fibers — the cellular mechanism behind hypertrophy and repair.
Naturally produced at the site of mechanical load. Injected MGF (short half-life) mimics the local post-workout surge; PEG-MGF provides systemic exposure between workouts.
Though MGF shares the IGF-1 core sequence, its unique E-domain binds a distinct receptor on satellite cells. This is why MGF acts differently than IGF-1 LR3 despite the sequence overlap.
| Benefit | Evidence |
|---|---|
| Muscle repair | Rat studies: MGF accelerates recovery from injury via satellite-cell proliferation |
| Hypertrophy | Post-workout injection combined with resistance training shows satellite-cell proliferation in animal models |
| Cardiac repair | Preclinical data on post-MI tissue regeneration — independent research interest |
| Neuroprotection | Some evidence for nerve-cell survival after ischemia |
Human data are limited. The rationale is strong mechanistically, but well-controlled human trials haven’t validated the anecdotal bodybuilding results.
Build your protocol, log every dose, monitor your body's response, and get reminders so you never miss a dose.
Start Tracking FreePEG-MGF is more practical for non-training days and for users who can’t dose post-workout.
2 mg vial + 2 mL BAC water = 1000 mcg/mL
| Dose | Volume | Syringe Units |
|---|---|---|
| 100 mcg | 0.10 mL | 10 units |
| 200 mcg | 0.20 mL | 20 units |
| 250 mcg | 0.25 mL | 25 units |
Use our free peptide calculator to figure out your reconstitution volume, draw amount, and syringe units.
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Same caveat as IGF-1 analogs: satellite-cell activation and anabolic signaling apply to dysregulated tissues too. Any cancer history is an absolute contraindication.
MGF and PEG-MGF is a research peptide not approved by the FDA for human use. It is sold only as a research chemical, and StackTrax does not endorse or facilitate personal use.
Quality varies enormously among research-chemical suppliers. At minimum, look for:
StackTrax’s preferred partner NextGen Peptides does not currently carry MGF and PEG-MGFin their catalog, which is why you don’t see a direct purchase link here. Other major research-chemical suppliers carry it; we don’t specifically recommend one for this compound.
Build your protocol, log every dose, monitor your body's response, and get reminders so you never miss a dose.
Start Tracking FreeDisclaimer: This guide is for educational and informational purposes only and is not intended as medical advice, diagnosis, or treatment. The compounds discussed are not FDA approved for human use. Always consult a qualified healthcare provider before starting any new supplement or peptide protocol. StackTrax does not sell peptides or supplements directly — purchase links go to third-party vendors. StackTrax is not responsible for the products, quality, or business practices of any third-party vendor. This page contains affiliate links — StackTrax may earn a commission on purchases at no extra cost to you.
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StackTrax guides cover peptides and compounds that are not FDA-approved for the uses discussed. The dosing, reconstitution, and safety information is compiled from published research and community protocols for educational purposes only.
Before using any compound mentioned here, consult a qualified healthcare provider. StackTrax does not sell, prescribe, or recommend these substances for personal use.
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