PEG-MGF
IGF-1 splice variant analog (PEGylated Mechano Growth Factor)
A PEGylated form of mechano growth factor referenced in muscle and tissue-repair research.
Also referenced as: Mechano Growth Factor, MGF
Overview
PEG-MGF is a PEGylated form of Mechano Growth Factor (MGF), a splice variant of insulin-like growth factor 1 (IGF-1Ec in humans) produced in response to mechanical loading and muscle damage. The MGF peptide corresponds to the unique C-terminal E-domain of this IGF-1 splice variant; PEGylation is added to extend its otherwise very short half-life.
At a glance
What PEG-MGF does
PEG-MGF is a PEGylated (polyethylene-glycol-attached) form of Mechano Growth Factor, which is itself a splice variant of the IGF-1 gene (IGF-1Ec) produced locally by muscle in response to mechanical loading and damage. What makes MGF distinct from ordinary IGF-1 is its unique C-terminal E-domain (the MGF E-peptide): rather than acting purely through the IGF-1 receptor to drive differentiation, MGF's E-peptide signals muscle satellite cells (the resident muscle stem cells) to activate and proliferate, expanding the pool of cells available to repair and add nuclei to damaged fibers. It is, in effect, the local 'rescue' signal that launches muscle repair after injury.
Native MGF is degraded within minutes, so the PEGylation is the functional key: attaching PEG extends the half-life from minutes to several days, giving the E-peptide signal enough persistence to be studied and used experimentally. In cell and animal research, MGF/PEG-MGF drives satellite-cell proliferation more potently than mature IGF-1, and it delays the onset of myogenin expression (a differentiation marker), consistent with a role in keeping satellite cells in a proliferative, undifferentiated state before they commit to fusing — the opposite phase from what mature IGF-1 emphasizes. It has also been reported to delay satellite-cell senescence, which is why it is studied in the context of aging muscle and sarcopenia.
The evidence is preclinical (in-vitro and animal); no human clinical trials have been conducted, and PEG-MGF remains a research compound.
Effects reported in research
- Activated and stimulated proliferation of muscle satellite cells via the MGF E-peptide — more potently than mature IGF-1 (in-vitro/animal).
- Delayed myogenin expression, keeping satellite cells in a proliferative rather than differentiating state (cell studies).
- Extended signal duration from minutes to ~several days through PEGylation (its defining pharmacokinetic feature).
- Delayed satellite-cell senescence, relevant to aging-muscle/sarcopenia research (preclinical).
- Promoted muscle repair and regeneration in models of mechanical damage/injury.
- Acts as the local, load-induced IGF-1 splice-variant 'repair launch' signal, distinct from systemic IGF-1's differentiation role.
- No human clinical trials conducted; effects are preclinical and research-use only.
Effects listed reflect findings reported in the research literature — many in animal or in-vitro models. Listing an effect is not a claim of efficacy or a therapeutic indication in humans.
Mechanism of action
MGF is a splice variant of IGF-1 whose distinctive C-terminal E-domain is implicated in activating muscle satellite (stem) cells and promoting local muscle repair and hypertrophy after mechanical stress, with actions that appear partly independent of the classical IGF-1 receptor. PEGylation (attachment of polyethylene glycol) protects the peptide from rapid degradation and clearance, substantially extending its half-life compared with native MGF. Much of the mechanistic detail remains at the preclinical/research level.
Mechanistic description reflects published research-literature understanding. Much peptide research is preclinical (in-vitro or animal-model); mechanism in humans may differ and is not established for many compounds.
What it's studied for
Research contexts in which PEG-MGF appears in the literature. Listing a research area is not a claim of efficacy or a therapeutic indication.
Key characteristics
- Derived from the C-terminal E-domain of the IGF-1Ec (MGF) splice variant
- PEGylation greatly extends half-life versus native, rapidly cleared MGF
- Studied for satellite-cell activation and local muscle repair
- Some proposed actions appear partly independent of the classical IGF-1 receptor
- Mechanistic and pharmacokinetic data remain largely preclinical/incomplete
Reported research dosing reference only
Educational reference, not dosing guidance. The figures below summarize amounts reported in published research and research-community protocols, provided for educational and research context only. They are not medical advice, not a recommendation, and not instructions for human use. PEG-MGF is a research compound.
PEG-MGF is referenced in the research literature at roughly 200-400 mcg per administration, given less frequently than native MGF because of its extended half-life. These are reference figures for research context only, not dosing guidance for humans.
- Common research-protocol reference: ~200-400 mcg per subcutaneous dose
Pegylation extends the ~5-7 min native MGF half-life to hours/days; allows systemic (non-site-specific) administration. Reference figures only, not human dosing guidance.
How it compares
PEG-MGF is based on a mechanically induced IGF-1 splice variant (MGF) rather than mature IGF-1, and PEGylation gives it a long half-life while the peptide's focus is local muscle repair via satellite cells.
Commonly studied alongside
Compounds frequently researched together with PEG-MGF in the literature. Cross-referenced for research context — not a usage or combination recommendation.
Compare and calculate
Side-by-side pages for the pairings the literature already documents for PEG-MGF, plus the unit-conversion reference for a reconstituted vial. Factual comparisons of documented characteristics — not a recommendation to combine or use any compound.
Handling & Stability
Lyophilized peptides are stored cold, protected from light, and reconstituted only at the time of intended in-vitro work.
- Avoid repeated freeze-thaw cycles
- Verify supplier lot and Certificate of Analysis
- Follow institutional lab-safety protocols
Analytical & COA Concepts
Reputable research suppliers publish a third-party Certificate of Analysis per batch. Key analytical concepts referenced in COAs include:
Category Context
PEG-MGF sits in the Growth & GH-Axis area of the PeptiDex library.
- Entry type: Research compound reference
- Growth & GH-Axis category hub →
- Browse the full library →
- Glossary of terms →
Where researchers source PEG-MGF
For researchers studying PEG-MGF, third-party suppliers such as Practically Natty Peptides offer research-grade material, third-party tests every batch and provides Certificates of Analysis on request, and ship from the US.
PeptiDex does not maintain a direct supplier listing for this compound. The link above goes to a third-party research-supplier directory.
Frequently asked questions
What is PEG-MGF?
PEG-MGF is a pegylated form of Mechano Growth Factor (MGF), itself a 24-amino-acid C-terminal splice variant of IGF-1 (IGF-1Ec) produced in response to mechanical stress. Attaching a polyethylene glycol (PEG) group greatly extends its otherwise very short circulating half-life.
How does PEG-MGF differ from regular MGF?
Native MGF has a half-life of only about 5-7 minutes, limiting it to localized action. PEGylation extends the half-life substantially (reported hours to days), so PEG-MGF is studied for systemic subcutaneous administration rather than the site-specific injection unmodified MGF requires.
How does MGF relate to IGF-1?
MGF is an alternative splice variant of the IGF-1 gene (IGF-1Ec) with a unique C-terminal peptide. It is studied for a distinct role in activating muscle satellite cells and tissue repair, separate from the systemic growth signaling of mature IGF-1.
What does PEG-MGF's extended half-life mean for research?
Because pegylation prolongs circulation, research protocols reference less frequent dosing (often a few times per week) and systemic rather than localized administration, in contrast to native MGF's short-acting, injection-site-limited profile.
Is PEG-MGF an approved drug?
No. PEG-MGF is not an approved medication and is available only as a research chemical for preclinical and in-vitro study.
Answers are educational summaries of research-literature context and do not constitute medical advice. See the Research Library, COA guide, and Storage & Handling guide for more.
References
Primary literature indexed in PubMed for PEG-MGF. Listing a study records that it exists and is indexed — it is not a claim of efficacy, a therapeutic indication, or an endorsement of its conclusions. Much of this literature is preclinical (in-vitro or animal-model).
- Mechano Growth Factor E peptide (MGF-E), derived from an isoform of IGF-1, activates human muscle progenitor cells and induces an increase in their fusion potential at different ages
- A new pro-migratory activity on human myogenic precursor cells for a synthetic peptide within the E domain of the mechano growth factor
Each reference was checked against its PubMed record on 2026-07-28: the PMID resolves and the title, journal and year match. Where no indexed literature exists for a compound, PeptiDex says so rather than substituting a citation about a different molecule. See the editorial policy.