What it is
PEG-MGF is a PEGylated form of Mechano Growth Factor (MGF), a splice variant of IGF-1 (IGF-1Ec) expressed by muscle after mechanical overload. PEGylation, the attachment of polyethylene glycol chains to a molecule, is intended to extend an otherwise very short half-life.
The evidence is preclinical, and there are no human clinical trials of the compound. In the PeptidesAI encyclopedia it is categorized under growth hormone and healing.
How it's thought to work
The MGF C-terminal peptide is thought to activate muscle satellite cells, the stem cells of muscle tissue, and support repair after mechanical damage, acting through a pathway distinct from classical IGF-1 receptor signaling. PEGylation slows clearance.
In rats, the MGF splice variant of the IGF-1 gene was expressed rapidly after local muscle damage, and its timing suggested to the authors that an initial pulse of MGF is responsible for satellite cell activation.
What the research says
Preclinical studies describe MGF's role in muscle repair after overload. In rat muscle, MGF was rapidly expressed after local damage, in a pattern the authors linked to satellite cell activation.
Not all laboratories have reproduced these effects: a study at two pharmaceutical companies found that MGF peptides did not increase proliferation of human or mouse muscle cells in culture, and its authors questioned whether MGF has a physiological role.
There are no human clinical trials of PEG-MGF, and it is not FDA-approved.
Reported side effects
Human safety data is minimal. Theoretical concerns follow from growth-factor signaling generally.
Reconstitution
PEG-MGF is supplied as a lyophilized (freeze-dried) powder and is typically reconstituted with bacteriostatic (BAC) water before use. It commonly comes in 2 mg and 5 mg vials. The amount of peptide in the vial is fixed; the water added only changes how concentrated the solution is.
Worked example. A 2 mg vial is 2,000 mcg. Reconstituted with 2 mL of BAC water, that works out to 2,000 mcg ÷ 2 mL = 1,000 mcg/mL. On a U-100 insulin syringe, where each unit is 0.01 mL, each unit holds 1,000 × 0.01 = 10 mcg. Use the peptide reconstitution calculator to work out the concentration and units for any vial size and water volume.
Important notes
PEG-MGF has no human clinical data. It is sold only as a research chemical, is not FDA-approved and is listed as prohibited by the World Anti-Doping Agency (WADA).
Sources
- Expression and splicing of the insulin-like growth factor gene in rodent muscle is associated with muscle satellite (stem) cell activation following local tissue damage. Hill M et al. The Journal of Physiology, 2003. Preclinical
- 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. Fornaro M et al. American Journal of Physiology - Endocrinology and Metabolism, 2014. Preclinical
Frequently asked questions
These questions cover the same ground as the sections above, in a shorter format.
What is PEG-MGF?
A PEGylated form of mechano growth factor, a splice variant of IGF-1 expressed by muscle after mechanical overload; the evidence is preclinical.
How is PEG-MGF thought to work?
The MGF peptide is thought to activate muscle satellite cells and support repair after mechanical damage, through a pathway distinct from classical IGF-1 receptor signaling; PEGylation slows clearance.
What does the research on PEG-MGF say?
Rat studies link MGF expression to satellite cell activation after damage, one laboratory study could not reproduce MGF peptide effects in cell culture, and there are no human clinical trials.
What are the reported side effects of PEG-MGF?
Human safety data is minimal; theoretical concerns follow from growth-factor signaling generally.
How much is one unit from a 2 mg PEG-MGF vial?
With 2 mL of BAC water, a 2 mg vial is 1,000 mcg/mL, so one unit on a U-100 syringe (0.01 mL) holds 10 mcg.
The full entry, plus the calculator
The PeptidesAI app has the complete encyclopedia entry for PEG-MGF — one of 70 compounds covered — plus the reconstitution calculator, a dose log and reminders. Free to download on iPhone.
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