PEG-MGF
Pegylated Mechano Growth Factor
Also known as: PEG-MGF
A pegylated version of an IGF-1 splice variant studied in animals for muscle repair and satellite cell activation after damage.
Overview
Mechano Growth Factor is a splice variant of IGF-1 produced by muscle in response to mechanical stress that helps activate repair. PEG-MGF is a pegylated form designed to last longer in circulation. Animal research points to roles in muscle repair and satellite cell recruitment, but human clinical evidence is limited. It is not approved and is prohibited in sport.
Mechanism of action
Activates muscle satellite cells and supports repair after mechanical damage; pegylation extends its short natural half-life.
Key studies & citations
- Animal2003
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
After muscle damage in rats, the MGF splice variant was expressed rapidly and transiently, preceding satellite cell activation markers and the slower rise in systemic IGF-IEa.
Journal of Physiology - Human2003
Expression of IGF-I splice variants in young and old human skeletal muscle after high resistance exercise
Heavy resistance exercise raised MGF mRNA in muscle of young but not elderly volunteers; a study of endogenous expression, not of injected PEG-MGF.
Journal of Physiology - Review2026
The emerging landscape of performance-enhancing peptides modulating GH-IGF1 axis: bridging the gap between clinical evidence and patient self-administration
Review covering PEG-MGF among GH/IGF-1 axis peptides: no controlled human trials of the pegylated product, and WADA prohibition applies.
Frontiers in Endocrinology
Frequently asked questions
Is PEG-MGF allowed in sport?
No. As an IGF-1 related growth factor it is on the WADA prohibited list at all times.