MGF (Mechano Growth Factor) is a splice variant of IGF-1, specifically the E-domain peptide of the IGF-1Ec isoform. It is produced naturally in mechanically stressed muscle tissue and plays a role in muscle repair and satellite cell activation. The synthetic, non-PEGylated form has an extremely short half-life in vivo (minutes), severely limiting its practical utility compared to the PEGylated version (PEG-MGF). It is a research compound with no clinical trials and is banned by WADA.
Category: Growth Factor. Evidence rating: D (animal/preclinical only).
Clinical status: Preclinical only. No human clinical trials.
MGF is expressed as part of the IGF-1 gene through alternative splicing in response to mechanical overload or tissue damage. The E-domain peptide (distinct from the mature IGF-1 peptide) activates satellite cells — muscle stem cells that donate nuclei to growing or repairing muscle fibers. It…
Safety considerations: No human safety data exists; Theoretical risks include uncontrolled cell proliferation; Extremely short half-life of the non-PEGylated form may limit both efficacy and toxicity.
Reviewed by the PeptideAtlas Editorial Team. Last reviewed: 2026-07-05.
Related peptides: IGF-1 LR3, Follistatin 344, IGF-1 DES.
Compare: MGF vs IGF-1 LR3, MGF vs Follistatin 344, MGF vs IGF-1 DES.
MGF is the native (non-PEGylated) E-domain peptide of the IGF-1Ec splice variant. PEG-MGF has a polyethylene glycol chain attached to extend its half-life from minutes to several hours. PEG-MGF is more commonly used in research contexts because native MGF is degraded too rapidly to have significant systemic effects.
No. MGF is the E-domain peptide produced by alternative splicing of the IGF-1 gene. While it comes from the same gene, it is a distinct peptide with different biological activity. MGF primarily activates satellite cells, whereas mature IGF-1 has broader anabolic and metabolic effects.
MGF (Mechano Growth Factor) is a splice variant of IGF-1 that is produced in response to muscle stretching and damage. It plays a key role in muscle repair and hypertrophy.
MGF (Mechano Growth Factor) has been studied for: Muscle repair, Satellite cell activation, Local tissue recovery, Hypertrophy support. Splice variant of IGF-1; released during muscle damage for local repair.
Activates satellite cells and muscle stem cells for repair. Unlike IGF-1, MGF is produced locally in damaged tissue and has specific muscle-building signaling properties.