PEG-MGF
Pegylated Mechano Growth Factor (PEGylated IGF-1Ec E-domain peptide). Synonyms: PEG-MGF, Pegylated MGF, PEGylated Mechano-Growth Factor, MECHA-FACTO (brand name, DenikPharm).
PEG-MGF is a PEGylated form of Mechano Growth Factor (IGF-1Ec), an IGF-1 splice variant produced in muscle after mechanical load. It activates satellite cells for muscle repair and regeneration. All published evidence is preclinical; no human clinical trials exist (Zablocka et al., Front Endocrinol 2012, PMC3485521).
Last updated: 2026-03-13
Safety Summary
CRITICAL CAVEAT: All side effect frequency estimates for PEG-MGF are from vendor/product summaries, community/anecdotal reports, and extrapolation from related PEGylated compounds -- NOT from controlled human clinical trials, which do not exist for PEG-MGF. No reproducible peer-reviewed body of evidence documents frequent or clearly attributable serious adverse events (SAEs) for PEG-MGF in humans. FDA FAERS and EMA EudraVigilance public databases returned no identifiable spontaneous-report signals for PEG-MGF as of March 2026. Class-level immunogenicity risks are salient: anti-PEG antibodies (IgM/IgG) can be pre-existing or treatment-induced, may cause accelerated blood clearance (ABC) and loss of efficacy, and can predispose to hypersensitivity or CARPA reactions (PMC12388889). Theoretical long-term risks include the promotion of undetected tumor growth due to the potent proliferative mechanism. Long-term human safety data are effectively absent. Unregulated sourcing and variable product purity in research/consumer markets create ongoing safety concerns.
Known Side Effects
common
common
uncommon
uncommon
uncommon
uncommon
rare
Who Should NOT Use This
MGF activates IGF-axis signaling (IGF-1R, PI3K/AKT) which promotes cell proliferation; theoretical risk of stimulating tumor growth. Vendor labels explicitly contraindicate use with active/recent neoplasm (Zablocka et al., PMC3485521).
No controlled human pregnancy outcome studies exist. Product labels advise against use during pregnancy/lactation.
Vendor labeling contraindicates use during critical acute illness.
Growth factor activity may exacerbate proliferative retinal conditions.
Interference with the IGF-axis during growth and development. Highly contraindicated in children and adolescents.
Glucocorticoids can attenuate the anabolic/growth-promoting effects of IGF-related agents (antagonism of anabolic signaling). Noted as an interaction in vendor labeling.
Pre-existing anti-PEG antibodies from prior PEGylated drug exposure may alter pharmacokinetics and safety profile, potentially causing accelerated clearance or hypersensitivity reactions (PMC12388889).
No PEG-MGF-specific dose-adjustment or safety studies exist. PEGylated peptides undergo proteolytic catabolism and altered clearance is theoretically possible in severe organ dysfunction.
Talk to Your Doctor
Before considering PEG-MGF, discuss it with your healthcare provider. Ask about potential interactions with your current medications, whether it is appropriate for your health conditions, and what monitoring may be needed.
Sources: [1-11]
Evidence Assessment
Preclinical only. No registered human clinical trials of PEG-MGF were identified on ClinicalTrials.gov, WHO ICTRP, or EU Clinical Trials Register as of March 2026. No peer-reviewed human pharmacokinetic, efficacy, or safety studies exist. The evidence base consists entirely of in vitro cell studies, animal models (rodent, rabbit), vendor/product information, and community anecdotal reports.
1Mechano-Growth Factor: an important cog or a loose screw in the repair machinery?
Zablocka B, Goldspink G, et al. - Frontiers in Endocrinology (2012) - Review - N/A (review)
Comprehensive review of MGF (IGF-1Ec) biology. MGF is produced in muscle after mechanical load, activates satellite cells, and signals through PI3K/AKT and MAPK/ERK pathways. E-domain may have IGF-1R-independent signaling. Tissues investigated include skeletal muscle, heart, bone, cartilage, dental ligament, and brain.
Limitations: Review article, not original experimental data. Does not specifically address PEG-MGF pharmacokinetics or clinical outcomes.
2Potency of Full-Length MGF to Induce Maximal Activation of the IGF-I R Is Similar to Recombinant Human IGF-I at High Equimolar Concentrations
Janssen JAMJL et al. - PLoS One (2016) - In vitro (kinase receptor activation bioassays) - N/A (in vitro assays)
Full-length MGF EC50 at IGF-1R = 7.83 nM (95% CI 4.87-12.58 nM); IGF-1 EC50 = 0.86 nM (~9.1-fold difference). MGF EC50 at IR-A = 73.11 nM; IR-B = 35.10 nM. Maximal activation by MGF comparable to IGF-1 at high equimolar concentrations. Goldspink-derived stabilized MGF analogue showed no measurable IGF-1R activation.
Limitations: In vitro bioassay only. Does not test PEGylated forms. Cell-based assay may not fully recapitulate in vivo receptor activation dynamics.
3Sustained delivery of MGF peptide from microrods attracts stem cells and reduces apoptosis of myocytes
Doroudian NM et al. - Biomedical Microdevices (2014) - Preclinical (in vitro/ex vivo, PEG-based delivery system) - N/A (preclinical)
PEG-based PEGDMA microrods used to deliver MGF E-peptide produced sustained local bioactivity, attracted stem cells, and reduced myocyte apoptosis.
Limitations: Preclinical model only. Uses PEGDMA microrod delivery system, not a simple PEG-conjugated MGF peptide. No human data.
4Localized Delivery of Mechano-Growth Factor E-domain Peptide via Polymeric Microstructures Improves Cardiac Function following Myocardial Infarction
Pena JL et al. - Biomaterials (2015) - Preclinical (rodent myocardial infarction model) - N/A (animal model)
Localized delivery of MGF E-domain peptide via polymeric microstructures improved cardiac function following myocardial infarction in rodent models.
Limitations: Animal model. Delivery system is polymeric microstructures, not simple PEGylation. No human cardiac outcomes data.
5Mechano-growth factor accelerates the proliferation and osteogenic differentiation of rabbit mesenchymal stem cells through the PI3K/AKT pathway
Tong Y et al. - BMC Biochemistry (2015) - Preclinical (in vitro, rabbit mesenchymal stem cells) - N/A (in vitro)
MGF accelerates proliferation and osteogenic differentiation of rabbit mesenchymal stem cells through PI3K/AKT signaling pathway.
Limitations: Rabbit cell culture. Does not test PEG-MGF. In vitro only.
6MGF E domain peptides activate satellite cells and support muscle regenerationPMID 21354439
Kandalla PK et al. - Not specified in raw data (2011) - Preclinical (in vitro, human satellite cells) - N/A (in vitro)
MGF E-domain peptides activate satellite cells in human primary muscle progenitor cell cultures and support muscle regeneration processes.
Limitations: In vitro study on human cells, not a clinical trial. Does not test PEG-MGF.
7Mechano growth factor, a splice variant of IGF-1, promotes neurogenesis in the aging mouse brainPMID 28683812
Tang JJ et al. - Molecular Brain (2017) - Preclinical (in vivo, aged mouse model) - N/A (animal study)
MGF promotes neurogenesis in the aging mouse brain, increasing proliferation in neurogenic niches and supporting neuronal survival.
Limitations: Mouse model only. Does not test PEG-MGF. No human neurological outcomes data.
8Cardiac repair after myocardial infarction with MGF-derived peptidesPMID 17581790
Carpenter V et al. - Not specified in raw data (2008) - Preclinical (rodent myocardial infarction model) - N/A (animal model)
MGF-derived peptides activate IGF-1R-linked pro-survival signaling, reduce cardiomyocyte apoptosis and pathological remodeling after ischemic cardiac injury.
Limitations: Preclinical only. Animal model, not human. Does not directly test PEG-MGF.
9Mechano growth factor attenuates mechanical overload-induced nucleus pulposus cell apoptosis through inhibiting the p38 MAPK pathway
Xu H et al. - Bioscience Reports (2019) - Preclinical (in vitro, nucleus pulposus cells) - N/A (in vitro)
Reported PEG-MGF attenuates mechanical overload-induced apoptosis via p38 MAPK inhibition. WARNING: This study has been RETRACTED and must be interpreted accordingly.
Limitations: RETRACTED PAPER. Findings should not be relied upon. In vitro only.
10MGF overexpression modulates inflammatory cell dynamics during muscle repair
Sun KT et al. - Frontiers in Physiology (2018) - Preclinical (in vivo, mouse skeletal muscle injury model) - N/A (animal model)
MGF overexpression modulates cytokine expression, influences macrophage apoptosis/resolution, and alters the inflammatory phase during muscle tissue repair.
Limitations: Animal model only. Uses transgenic overexpression, not exogenous PEG-MGF administration.
11Mechano growth factor E peptide promotes osteoblasts proliferation and bone-defect healing in rabbits
Not specified in raw data - Not specified (2011) - Preclinical (in vivo, rabbit bone defect model) - N/A (animal model)
MGF E-peptide promotes osteoblast proliferation and accelerates bone defect healing in rabbit models.
Limitations: Rabbit model. Does not directly test PEG-MGF.