library.onepin.app/peg-mgf Peptide Education Library
Education only, not medical advice 21+ Every dose is an example to finalize with a licensed provider

OnePin Peptide Library · Repair & Recovery

Repair & Recovery Peptide Not FDA-approved · investigational

PEG-MGF

PEGylated MGF · Pegylated MGF

PEG-MGF (PEGylated Mechano Growth Factor) is a synthetic, PEGylated variant of MGF (Mechano Growth Factor), which is itself a splice variant of IGF-1 (specifically the IGF-1Ec isoform in humans). Natural MGF is produced locally in muscle tissue in response to mechanical overload (resistance exercise) or tissue damage. It activates muscle satellite cells - the resident stem cells responsible for muscle repair, regeneration, and hypertrophy. However, natural MGF has an extremely short half-life (minutes), limiting its therapeutic utility.,PEGylation (attachment of a polyethylene glycol chain) extends the biological half-life from minutes to several hours, allowing systemic administration via intramuscular injection. PEG-MGF is used in research and biohacking contexts for muscle growth, injury recovery, and tissue repair. It represents a more targeted approach than full-length IGF-1, as MGF specifically activates satellite cell proliferation without the broader metabolic and potential pro-cancer effects of systemic IGF-1 elevation.,PEG-MGF is distinct from IGF-1 LR3 (which mimics the systemic IGF-1Ea isoform) in that it targets the early phase of muscle repair - satellite cell activation and proliferation - rather than the later phase of differentiation and protein synthesis. In practice, some protocols alternate PEG-MGF and IGF-1 LR3 to cover both phases of the muscle growth response.

Quick Start
Route
IM (intramuscular)
Start low
200mcg
Frequency
1x daily on training days or 2-3x per week
Timing
Anytime

Inject IM into the target muscle group immediately post-workout for localized effect. Reconstitute with bacteriostatic water. Use insulin syringe for precise dosing.

Start here. Every protocol below is ordered lowest-first. Begin at the smallest effective dose, hold about a week to assess tolerance, and step up only if needed.

Tiered Protocols · lowest first
Quick Start
Conservative start
200mcg · IM (intramuscular) · 1x daily on training days or 2-3x per week
Lowest starting point. Hold about a week to assess tolerance before stepping up.
200mcg
1x daily on training days or 2-3x per week
Intermediate
Systemic Recovery
200-400 mcg · SubQ · 2x Weekly
anecdotal · community
200-400 mcg
2x Weekly
01

How it works

MGF (Mechano Growth Factor) is an autocrine splice variant of IGF-1, produced locally in muscle tissue after mechanical overload or damage. The unique C-terminal E domain of MGF (24 amino acids differing from IGF-1Ea) is responsible for its satellite cell activating properties. MGF binds to a distinct receptor (not the IGF-1R) on muscle satellite cells, triggering their activation from quiescence (G0) into the cell cycle.,Upon activation, satellite cells proliferate (expanding the pool of myogenic precursors) and then, under influence of other growth factors including IGF-1Ea, differentiate into myoblasts that fuse with existing muscle fibers or form new fibers. This process is essential for muscle hypertrophy, repair, and regeneration. MGF specifically drives the proliferation phase - creating more satellite cells - while IGF-1Ea drives the differentiation and fusion phase.,PEGylation extends the circulating half-life from ~5-7 minutes (unmodified MGF) to several hours, enabling effective dosing via intramuscular injection. The PEG chain protects the peptide from enzymatic degradation without significantly altering receptor binding. PEG-MGF can act both locally (when injected into specific muscle groups) and systemically to promote satellite cell activation throughout the body.

MGF (Mechano Growth Factor) is an autocrine splice variant of IGF-1, produced locally in muscle tissue after mechanical overload or damage. The unique C-terminal E domain of MGF (24 amino acids differing from IGF-1Ea) is responsible for its satellite cell activating properties. MGF binds to a distinct receptor (not the IGF-1R) on muscle satellite cells, triggering their activation from quiescence (G0) into the cell cycle.,Upon activation, satellite cells proliferate (expanding the pool of myogenic precursors) and then, under influence of other growth factors including IGF-1Ea, differentiate into myoblasts that fuse with existing muscle fibers or form new fibers. This process is essential for muscle hypertrophy, repair, and regeneration. MGF specifically drives the proliferation phase - creating more satellite cells - while IGF-1Ea drives the differentiation and fusion phase.,PEGylation extends the circulating half-life from ~5-7 minutes (unmodified MGF) to several hours, enabling effective dosing via intramuscular injection. The PEG chain protects the peptide from enzymatic degradation without significantly altering receptor binding. PEG-MGF can act both locally (when injected into specific muscle groups) and systemically to promote satellite cell activation throughout the body.

02

What to expect

Early
Days 1–7

Days 1-7: Satellite cell activation occurring at the cellular level. Subtle recovery improvements possible.

03

Evidence

HumanNo published trials
AnimalPresent
In-vitroPresent
2012Mechano-Growth Factor: an important cog or a loose screw in the repair machinery? · Brisson BK, Barton ER, Frontiers in Endocrinology ↗review
2011Mechano 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 · Kandalla PK et al, Mechanisms of Ageing and Development ↗peer reviewed
2010Minireview: Mechano-growth factor: a putative product of IGF-I gene expression involved in tissue repair and regeneration · Goldspink G, Endocrinology ↗review
2014Mechano-growth factor peptide, the COOH terminus of unprocessed insulin-like growth factor 1, has no apparent effect on myoblasts or primary muscle stem cells · Fornaro M et al, American Journal of Physiology - Endocrinology and Metabolism ↗peer reviewed
04

Interactions & stacking

What's safe to combine, and what belongs in a separate pin.

Safe & synergistic

GH (Growth Hormone)GH creates a favorable anabolic environment and increases local IGF-1 production, which may enhance MGF's satellite cell activation response
CJC-1295/IpamorelinGHRH/GHRP peptides increase endogenous GH secretion, supporting the broader anabolic environment for MGF-mediated muscle growth
IGF-1 LR3PEG-MGF activates satellite cell proliferation while IGF-1 LR3 promotes differentiation and protein synthesis - covering both phases of the muscle growth response
BPC-157BPC-157's tissue repair and angiogenesis effects complement MGF's satellite cell activation for accelerated muscle and tendon recovery

Keep separate

Insulin (high-dose, concurrent)High-dose insulin may drive premature satellite cell differentiation, counteracting MGF's proliferative signal. Temporal separation recommended
05

Pharmacokinetics

Illustrative plasma concentration · 24 h
Half-life
~30 minutes to several hours (PEGylated form, estimated). Unmodified MGF half-life is ~5-7 minutes.
Peak · Tmax
~15-30 minutes IM (estimated)
Elimination
~6-12 hours (estimated for PEGylated form)
Activity
Satellite cell activation signal: hours. Satellite cell proliferation response: 24-72 hours post-injection. Newly formed satellite cells persist long-term.

Storage. Store lyophilized powder at -20C for long-term storage or 2-8C (refrigerated) for short-term. After reconstitution with bacteriostatic water, store at 2-8C and use within 30 days. Avoid repeated freeze-thaw cycles. Protect from light.

06

Regulatory status

Not FDA-approved for any indication. Available as a research peptide only (sold 'for research purposes' or 'not for human consumption'). Listed as a prohibited substance by WADA (World Anti-Doping Agency) under S2 - Peptide Hormones, Growth Factors. No pharmaceutical-grade product exists. Purity varies between research suppliers.

Put it to work

Calculate, log & track

Open PEG-MGF straight into OnePin with your vial and dose pre-filled, then let it handle the syringe math and remind you before the vial runs out.

Open PEG-MGF in the app →

Go deeper

The guide & community

The complete PEG-MGF walkthrough, real protocol discussion and coaching live inside the BlessUp community on Skool.

Join the community ↗
Open in app Community