PEG-MGF
Also called: mechano growth factor
Clinical reviewer: Jacob Moore, MD · Last checked September 22, 2026
What is PEG-MGF?
PEG-MGF is the pegylated form of mechano growth factor, a splice variant of IGF-1 the body produces after resistance exercise. Unmodified MGF is studied in cell and animal research for tissue repair; PEG-MGF itself is sold online as a self-administered IGF-1 analogue. It is not FDA-approved, and our search as of September 2026 found no human study of it.
How is PEG-MGF different from MGF?
PEG-MGF is the pegylated form of mechano growth factor (MGF), a splice variant of the IGF-1 gene the body expresses after mechanical loading [1]. In a study of resistance exercise, MGF mRNA rose significantly in young adults aged 25 to 36 but not in elderly subjects aged 70 to 82 [1]. That study measured the body's own MGF gene expression; nobody in it received MGF or PEG-MGF as a drug.
Is there human research on PEG-MGF itself?
Not that we could find. A narrative review lists pegylated mechano growth factor among IGF-1 analogues used in online self-administration protocols, alongside other research compounds, but flags an absence of regulatory approval and uncertainty over product composition, dose and stacking practices [2]. No human study of PEG-MGF was found in our search as of September 2026.
What is PEG-MGF's FDA and WADA status?
Not FDA-approved. FDA's list current as of May 14, 2026 places unpegylated mechano growth factor in Category 3, bulk substances nominated without adequate support [3]. FDA has scheduled Pegylated Mechano Growth Factor for advisory-committee review, alongside four other substances, before the end of February 2027; that recommendation would still be non-binding [4].
Related terms
Sources
- Hameed M et al. Expression of IGF-I splice variants in young and old human skeletal muscle after high resistance exercise. Journal of Physiology, 2003.
- Dominikowski A et al. The emerging landscape of performance-enhancing peptides modulating GH-IGF1 axis, bridging the gap between clinical evidence and patient self-administration. Frontiers in Endocrinology, 2026.
- FDA — Bulk Drug Substances Nominated for Use in Compounding Under Section 503A (categories list), updated May 14, 2026
- FDA — Meeting of the Pharmacy Compounding Advisory Committee (upcoming), content current as of April 15, 2026
This entry is for education and is not medical advice. Talk with a licensed clinician about your own situation before starting, stopping, or changing any treatment.
