MGF
Muscle-specific IGF-1 splice variant — activated by mechanical loading, drives satellite cell activation and muscle repair.
Research facts
| Half-life | ~minutes (native form) / extended with PEGylation |
|---|---|
| Route | IM (localised) |
| Typical dose | 100–200 mcg per injection site |
| Frequency | Post-workout IM |
| Solvent | Bacteriostatic water |
| pH | 5.5–7.5 |
| Stability | 30 days at +4°C |
Mechanism of action
MGF (Mechano Growth Factor) is an alternatively spliced form of IGF-1 (the IGF-1Ec isoform) produced locally in muscle and other tissues in response to mechanical loading and exercise. The E-peptide region unique to MGF activates muscle satellite cells (muscle stem cells) — driving them from quiescence into a proliferative state, increasing the myonuclei pool. After E-peptide cleavage, the mature IGF-1 domain promotes differentiation and protein synthesis. MGF is the body's primary mechanism for exercise-induced muscle hypertrophy — the satellite cell activation response to resistance training.
Documented effects (research-model)
- Activates muscle satellite cells (the body's muscle repair stem cells)
- Increases myonuclei number — permanent hypertrophy potential
- Expressed locally in response to exercise (physiological process)
- Potential in muscle atrophy prevention research
Research protocols
| Protocol | Dose | Frequency | Cycle | Vial |
|---|---|---|---|---|
| Experimental | 100–200 mcg IM per muscle group | 1–2× weekly post-workout | 4–8 weeks | 2mg / 2mL BAC water |
Research context only. Not medical advice. Consult a qualified healthcare professional before any protocol decision.
Synergies
- IGF-1 LR3 MODERATE
MGF activates satellite cells (myonuclei expansion); IGF-1 LR3 drives protein synthesis and differentiation in those activated cells. Sequential mechanism.
Myths & misconceptions
Evidence gaps
- No human RCT data for injectable MGF.
- Native MGF has extremely short half-life — PEGylated MGF has longer half-life but changes pharmacodynamics.
- Interaction between injected MGF and exercise-induced endogenous MGF unknown.
Safety notes
Very limited human safety data. Strong mitogenic properties — avoid in any malignancy history. Localised injection carries the same caveats as IGF-1 DES. Research context only.
Biomarkers to monitor
Primary-source citations
- PMID 21474296 — Mechano Growth Factor: multiple roles and tissue-specific expression (J Cell Physiol. 2011)
Frequently asked
What is MGF?
MGF (Mechano Growth Factor — IGF-1Ec Splice Variant) is a research compound classified in our library as Tier D — Animal or in-vitro data only.. Muscle-specific IGF-1 splice variant — activated by mechanical loading, drives satellite cell activation and muscle repair.
What is the evidence tier for MGF?
We classify MGF as Tier D: Animal or in-vitro data only. See our full peptide evidence tiers explainer for how we assign S/A/B/C/D.
What is the research dose of MGF?
For MGF, typical research dose is 100–200 mcg per injection site, route is IM (localised), half-life is ~minutes (native form) / extended with PEGylation. Protocols vary by research goal — see the protocols section on this page for standard and advanced dosing schedules. Research use only, not medical advice.
Is MGF safe?
Very limited human safety data. Strong mitogenic properties — avoid in any malignancy history. Research context only — no compound on this site is approved for human therapeutic use unless explicitly noted.