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RUO · Research Use Only⚠ Cancer Concern+2 more

PEG MGF

A PEGylated synthetic copy of the IGF-1Ec splice variant produced by mechanically loaded muscle. We read all 60 studies. The protocol is below.

Updated 03 May 2026Read 12 minEvidence ●○○○○Citations 60
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Free — puts PEG MGF on your decision board.

The PEG MGF Report · $19

Everything you need to start: dose, sourcing, safety, our verdict.

One purchase · yours forever

Built from 60 cited studies.

Status
Research-only
Class
Cancer Concern
Evidence
1/ 5●○○○○
Randomized human trials
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FDA status
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WADA status
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⚠ Cancer Concern
Read this if
  • your bro-science source told you to stack PEG MGF with IGF-1 LR3 and you want the honest read on whether the stack adds anything
  • you started running peptides in the 2010s and PEG MGF was on your old protocol
  • you want to understand why it's basically a research chemical with less data than IGF-1 LR3
  • you're trying to verify whether what's in the vial is actually PEGylated (often it isn't)
Skip this if
  • **you have a personal or family history of cancer** — same IGF-1 receptor signaling, even less human data than LR3, do not run this
  • you compete in a tested sport — WADA-banned
  • you're under 30 and looking for a first GH-family peptide — start somewhere else
The 4 ways you can buy PEG MGF
Brand
✗
No FDA approval
Compounded 503A
✗
Not available
Not a recognized therapeutic; no 503A pathway.
RUO (research-only)
✓
Sold for research only
$60–$140/mo
Entire off-label market; identity, purity, PEGylation efficiency unverified.
Gray market
✓
Illegal to import for huma…
$17–$22/mo
Small gray market; PEGylation status almost never verified on the gray side.
Click any lane for the full Sourcing breakdown.
First 90 days · PEG MGF
Weeks 1–2
Nothing perceptible. The healing-acceleration effect — if it's going to work — isn't a week-one signal. If you 'feel something' immediately, that's expectation, not the peptide.
Weeks 4–8
Subtle improvement on the target injury if it's going to work. Range of motion, less morning stiffness, less acute pain on load.
Week 12 — decide
Honest decision point. Either the injury is materially better than the no-peptide trajectory would have been, or it isn't. The clinical literature in humans is thin enough that your n=1 trial IS the evidence base.
Quit if
  • Any unusual symptoms — especially relevant if you have a personal or family cancer history (angiogenesis mechanism for BPC-157, TB-500).
  • 12 weeks with no perceived improvement vs the no-peptide trajectory.
  • New pain or symptoms at injection site that don't resolve in 48 hours.
Identity

What it is.

PEG-MGF is pegylated mechano growth factor — a synthetic version of a splice variant of that the body produces locally in muscle tissue in response to mechanical stress (i.e., lifting heavy things). The native MGF is a brief, local signal involved in satellite-cell activation and muscle repair.

The "PEG" prefix means a polyethylene glycol chain has been attached to the molecule, extending its from minutes (native MGF clears almost immediately) to roughly 48 hours. That stabilizes it enough to be dosed as an injectable instead of staying as a transient autocrine signal.

It has no FDA approval and is not in any active human clinical program. Sold strictly as a research chemical (RUO) in the US, primarily marketed to bodybuilders. WADA-banned in and out of competition.

TL;DR

TL;DR. 30-second version.

The compressed verdict — what PEG MGF actually is, what the human evidence shows, and the watch-for in three bullets. Locked.

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Mechanism

Mechanism.

Mechanism · in the PEG MGF report

How the molecule actually works — receptor profile, downstream signaling, what to expect mechanistically.

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Evidence

Evidence. What we actually know in humans.

Evidence · in the PEG MGF report

The trial breakdown — phase, n, primary endpoint, who funded, what hit, what didn't.

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Human-Evidence Factbox
Randomized human trials
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FDA status
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WADA status
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Mechanism family
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Animal studies
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Cancer-concern channel
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Family-cancer-history users
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PEG MGF + IGF-1 LR3 stack data
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Quit-if marker
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Dose

Dose. The actual protocol.

Dose · in the PEG MGF report

The specific protocol — dose, titration schedule, cycle pattern, frequency, route.

We read 60 studies to write this report.
Get the report · $19 ↓
Sourcing

Sourcing. Where the cohort actually buys.

Sourcing · in the PEG MGF report

Sourcing breakdown — vendor methodology, red flags, our published test results, COA checklist.

We read 60 studies to write this report.
Get the report · $19 ↓
Safety

Safety. Side effects.

Safety · in the PEG MGF report

The watch-for list — contraindications, drug interactions, monitoring labs, when to stop.

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Editorial Position

Editorial position.

Editorial Position · in the PEG MGF report

Our editorial position — explicit yes / no / depends, with the reasoning behind it.

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Citations

Citations.

  1. 01Liu Y, et al. The role of mechano growth factor in chondrocytes and cartilage defects: a concise review. Acta biochimica et biophysica Sinica. 2023;55(5):701-712. PMID: 37171185.
  2. 02Feng F, et al. Mechano-growth factor regulates periodontal ligament stem cell proliferation and differentiation through Fyn-RhoA-YAP signaling. Biochemical and biophysical research communications. 2024;733:150450. PMID: 39067248.
  3. 03Solís C, et al. Mechano-growth factor E-domain modulates cardiac contractile function through 14-3-3 protein interactomes. Frontiers in physiology. 2022;13:1028345. PMID: 36467694.
  4. 04Podratz JL, et al. Mechano growth factor interacts with nucleolin to protect against cisplatin-induced neurotoxicity. Experimental neurology. 2020;331:113376. PMID: 32511954.
  5. 05Matheny RW Jr, et al. Minireview: Mechano-growth factor: a putative product of IGF-I gene expression involved in tissue repair and regeneration. Endocrinology. 2010;151(3):865-75. PMID: 20130113.
+Show all 60 citations
  1. 06Sha Y, et al. Mechano Growth Factor Accelerates ACL Repair and Improves Cell Mobility of Mechanically Injured Human ACL Fibroblasts by Targeting Rac1-PAK1/2 and RhoA-ROCK1 Pathways. International journal of molecular sciences. 2022;23(8). PMID: 35457148.
  2. 07Yi Q, et al. Splicing factor-modulated generation of mechano growth factor regulates physiological processes in osteoblasts under mechanical stimuli. Cell adhesion & migration. 2019;13(1):322-331. PMID: 31680616.
  3. 08Alagaratnam S, et al. Mechano-growth Factor Expression in Colorectal Cancer Investigated With Fluorescent Gold Nanoparticles. Anticancer research. 2019;39(4):1705-1710. PMID: 30952709.
  4. 09Ma Y, et al. Mechano growth factor pretreatment yield mechanical stimuli induced cell stress responses in ligament fibroblasts of osteoarthritis via activating ATF-2. Biotechnology letters. 2020;42(8):1337-1349. PMID: 32222864.
  5. 10Tang JJ, et al. Mechano growth factor, a splice variant of IGF-1, promotes neurogenesis in the aging mouse brain. Molecular brain. 2017;10(1):23. PMID: 28683812.
  6. 11Zhang B, et al. [Expression of mechano-growth factor and its roles in tissue repairs and regeneration]. Zhongguo xiu fu chong jian wai ke za zhi = Zhongguo xiufu chongjian waike zazhi = Chinese journal of reparative and reconstructive surgery. 2012;26(5):617-20. PMID: 22702061.
  7. 12He J, et al. Mechano growth factor E peptide inhibits invasion of melanoma cells and up-regulates CHOP expression via endoplasmic reticulum stress. Biotechnology letters. 2018;40(1):205-213. PMID: 28986701.
  8. 13Jing X, et al. Mechano-growth factor protects against mechanical overload induced damage and promotes migration of growth plate chondrocytes through RhoA/YAP pathway. Experimental cell research. 2018;366(2):81-91. PMID: 29470961.
  9. 14Shang J, et al. The role of mechano-growth factor E peptide in the regulation of osteosarcoma. Oncology letters. 2015;10(2):697-704. PMID: 26622556.
  10. 15Sun KT, et al. Overexpression of Mechano-Growth Factor Modulates Inflammatory Cytokine Expression and Macrophage Resolution in Skeletal Muscle Injury. Frontiers in physiology. 2018;9:999. PMID: 30140235.
  11. 16Sha Y, et al. Pretreatment with mechano growth factor E peptide attenuates osteoarthritis through improving cell proliferation and extracellular matrix synthesis in chondrocytes under severe hypoxia. International immunopharmacology. 2021;97:107628. PMID: 34015701.
  12. 17Deng M, et al. Mechano growth factor E peptide promotes osteoblasts proliferation and bone-defect healing in rabbits. International orthopaedics. 2011;35(7):1099-106. PMID: 21057789.
  13. 18Song Y, et al. Surface modification of electrospun fibers with mechano-growth factor for mitigating the foreign-body reaction. Bioactive materials. 2021;6(9):2983-2998. PMID: 33732968.
  14. 19Song Y, et al. The use of mechano growth factor to prevent cartilage degeneration in knee osteoarthritis. Journal of tissue engineering and regenerative medicine. 2018;12(3):738-749. PMID: 28599103.
  15. 20Schlegel W, et al. Insulin-like growth factor I (IGF-1) Ec/Mechano Growth factor--a splice variant of IGF-1 within the growth plate. PloS one. 2013;8(10):e76133. PMID: 24146828.
  16. 21Xian CY, et al. [IGF-1 alternative splice isoforms: mechano growth factor]. Sheng li ke xue jin zhan [Progress in physiology]. 2005;36(4):322-4. PMID: 16408771.
  17. 22Carpenter V, et al. Mechano-growth factor reduces loss of cardiac function in acute myocardial infarction. Heart, lung & circulation. 2008;17(1):33-9. PMID: 17581790.
  18. 23Peña JR, et al. Localized delivery of mechano-growth factor E-domain peptide via polymeric microstructures improves cardiac function following myocardial infarction. Biomaterials. 2015;46:26-34. PMID: 25678113.
  19. 24Kravchenko IV, et al. Monoclonal antibodies to mechano-growth factor. Hybridoma (2005). 2006;25(5):300-5. PMID: 17044786.
  20. 25Riddoch-Contreras J, et al. Mechano-growth factor, an IGF-I splice variant, rescues motoneurons and improves muscle function in SOD1(G93A) mice. Experimental neurology. 2009;215(2):281-9. PMID: 19038252.
  21. 26Li H, et al. Mechano-growth factor enhances differentiation of bone marrow-derived mesenchymal stem cells. Biotechnology letters. 2015;37(11):2341-8. PMID: 26330369.
  22. 27Luo Q, et al. Mechano growth factor E peptide promotes rat bone marrow-derived mesenchymal stem cell migration through CXCR4-ERK1/2. Growth factors (Chur, Switzerland). 2015;33(3):210-9. PMID: 26260632.
  23. 28Zhang B, et al. Mechano-growth factor E peptide promotes healing of rat injured tendon. Biotechnology letters. 2016;38(10):1817-25. PMID: 27334712.
  24. 29Luo Z, et al. Mechano growth factor (MGF) and transforming growth factor (TGF)-β3 functionalized silk scaffolds enhance articular hyaline cartilage regeneration in rabbit model. Biomaterials. 2015;52:463-75. PMID: 25818452.
  25. 30Kandalla PK, et al. 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. Mechanisms of ageing and development. 2011;132(4):154-62. PMID: 21354439.
  26. 31Yu C, et al. [Study on the regulatory effects of mechano growth factor on soft tissue repair]. Sheng wu yi xue gong cheng xue za zhi = Journal of biomedical engineering = Shengwu yixue gongchengxue zazhi. 2015;32(1):235-9. PMID: 25997299.
  27. 32Chen H, et al. Intramuscular injection of mechano growth factor E domain peptide regulated expression of memory-related sod, miR-134 and miR-125b-3p in rat hippocampus under simulated weightlessness. Biotechnology letters. 2016;38(12):2071-2080. PMID: 27623796.
  28. 33Zabłocka B, et al. Mechano-Growth Factor: an important cog or a loose screw in the repair machinery?. Frontiers in endocrinology. 2012;3:131. PMID: 23125840.
  29. 34Liu M, et al. Potential effect of mechano growth factor E-domain peptide on axonal guidance growth in primary cultured cortical neurons of rats. Journal of tissue engineering and regenerative medicine. 2018;12(1):70-79. PMID: 27863093.
  30. 35Zhang B, et al. A synthetic mechano-growth factor E peptide promotes rat tenocyte migration by lessening cell stiffness and increasing F-actin formation via the FAK-ERK1/2 signaling pathway. Experimental cell research. 2014;322(1):208-16. PMID: 24434354.
  31. 36Wei X, et al. Improved Muscle Regeneration into a Joint Prosthesis with Mechano-Growth Factor Loaded within Mesoporous Silica Combined with Carbon Nanotubes on a Porous Titanium Alloy. ACS nano. 2022;16(9):14344-14361. PMID: 36053268.
  32. 37Wu J, et al. Mechano-growth factor induces migration of rat mesenchymal stem cells by altering its mechanical properties and activating ERK pathway. Biochemical and biophysical research communications. 2013;441(1):202-7. PMID: 24140053.
  33. 38Li H, et al. Mechano growth factor-E regulates apoptosis and inflammatory responses in fibroblast-like synoviocytes of knee osteoarthritis. International orthopaedics. 2015;39(12):2503-9. PMID: 26338342.
  34. 39Fornaro M, et al. Mechano-growth factor peptide, the COOH terminus of unprocessed insulin-like growth factor 1, has no apparent effect on myoblasts or primary muscle stem cells. American journal of physiology. Endocrinology and metabolism. 2014;306(2):E150-6. PMID: 24253050.
  35. 40Tong Y, et al. Mechano-growth factor accelerates the proliferation and osteogenic differentiation of rabbit mesenchymal stem cells through the PI3K/AKT pathway. BMC biochemistry. 2015;16:1. PMID: 25588515.
  36. 41Niu X, et al. Microencapsulation of mechano growth factor E peptide for sustained delivery and bioactivity maintenance. International journal of pharmaceutics. 2014;469(1):214-21. PMID: 24768406.
  37. 42Li C, et al. Increased IGF-IEc expression and mechano-growth factor production in intestinal muscle of fibrostenotic Crohn's disease and smooth muscle hypertrophy. American journal of physiology. Gastrointestinal and liver physiology. 2015;309(11):G888-99. PMID: 26428636.
  38. 43Ikeda S, et al. The effect of anabolic steroid administration on passive stretching-induced expression of mechano-growth factor in skeletal muscle. TheScientificWorldJournal. 2013;2013:313605. PMID: 24062630.
  39. 44van Dijk-Ottens M, et al. Thyroid hormone-induced cardiac mechano growth factor expression depends on beating activity. Endocrinology. 2010;151(2):830-8. PMID: 20032059.
  40. 45Cui H, et al. Mechano growth factor E peptide regulates migration and differentiation of bone marrow mesenchymal stem cells. Journal of molecular endocrinology. 2014;52(2):111-20. PMID: 24323763.
  41. 46Xin C, et al. Mechano-growth factor E peptide inhibits the differentiation and mineralization of osteoblasts. Archives of oral biology. 2012;57(6):720-7. PMID: 22186070.
  42. 47Kravchenko IV, et al. Stimulation of mechano-growth factor expression by second messengers. Archives of biochemistry and biophysics. 2011;507(2):323-31. PMID: 21192914.
  43. 48Quesada A, et al. C-terminal mechano growth factor protects dopamine neurons: a novel peptide that induces heme oxygenase-1. Experimental neurology. 2009;220(2):255-66. PMID: 19735655.
  44. 49Moro A, et al. Mechanical growth factor inhibited syndesmophyte formation and the progression of osteoarthritis and ankylosing spondylitis-like symptoms in HLA-B27/Hu-β2m transgenic rats. Arthritis research & therapy. 2025;27(1):218. PMID: 41272763.
  45. 50Kuznetsova TV, et al. Producing human mechano growth factor (MGF) in Escherichia coli. Protein expression and purification. 2008;58(1):70-7. PMID: 18068377.
  46. 51Chen JT, et al. [Mechano-growth factor regulated cyclic stretch-induced osteogenic differentiation and MMP-1, MMP-2 expression in human periodontal ligament cells by activating the MEK/ERK1/2 pathway]. Shanghai kou qiang yi xue = Shanghai journal of stomatology. 2019;28(1):6-12. PMID: 31080992.
  47. 52Imanaka M, et al. Growth hormone stimulates mechano growth factor expression and activates myoblast transformation in C2C12 cells. The Kobe journal of medical sciences. 2008;54(1):E46-54. PMID: 18772608.
  48. 53Lv Y, et al. Pretreatment with mechano-growth factor E peptide protects bone marrow mesenchymal cells against damage by fluid shear stress. Biotechnology letters. 2014;36(12):2559-69. PMID: 25129046.
  49. 54Goldspink G, et al. Effects of activity on growth factor expression. International journal of sport nutrition and exercise metabolism. 2001;11 Suppl:S21-7. PMID: 11915923.
  50. 55McBrier NM, et al. Therapeutic ultrasound decreases mechano-growth factor messenger ribonucleic acid expression after muscle contusion injury. Archives of physical medicine and rehabilitation. 2007;88(7):936-40. PMID: 17601477.
  51. 56Quesada A, et al. C-terminal mechano-growth factor induces heme oxygenase-1-mediated neuroprotection of SH-SY5Y cells via the protein kinase Cϵ/Nrf2 pathway. Journal of neuroscience research. 2011;89(3):394-405. PMID: 21259326.
  52. 57Xin J, et al. Functional and transcriptomic analysis of the regulation of osteoblasts by mechano-growth factor E peptide. Biotechnology and applied biochemistry. 2014;61(2):193-201. PMID: 24033831.
  53. 58Goldspink G. Gene expression in skeletal muscle. Biochemical Society transactions. 2002;30(2):285-90. PMID: 12023866.
  54. 59Iida K, et al. Muscle mechano growth factor is preferentially induced by growth hormone in growth hormone-deficient lit/lit mice. The Journal of physiology. 2004;560(Pt 2):341-9. PMID: 15308683.
  55. 60Mavrommatis E, et al. The E-domain region of mechano-growth factor inhibits cellular apoptosis and preserves cardiac function during myocardial infarction. Molecular and cellular biochemistry. 2013;381(1-2):69-83. PMID: 23712705.
The PEG MGF Report · $19

Everything you need to start.

Dose, sourcing, safety, our verdict. One purchase. Yours forever.

Built from 60 cited studies.

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