At a glance
- Mechanism of action
- MGF is generated by alternative splicing of the IGF-1 gene (isoform IGF-1Ec) and acts primarily locally at the site of mechanical load; its C-terminal E-peptide drives activation and proliferation of muscle progenitor cells in vitro.
- Benefits & use
- In preclinical models, MGF has been linked to satellite cell activation, muscle regeneration after injury, cardioprotection following ischemia and enhanced migration of bone-marrow-derived mesenchymal stem cells; human data remain very limited.
- Study status
- Evidence comes mainly from in vitro work on human satellite cells (e.g. Kandalla 2011) and animal models (mouse, rat, sheep); no controlled clinical trials with exogenous MGF in humans have been published, and one independent lab reported no effect of synthetic MGF E-peptide on myoblasts.
- Dosing note
- No approved human dose exists; experimental literature uses a wide range of model-dependent doses - this is not a dosing instruction, but a note that no clinically validated dose has been established.
MGF (Mechano Growth Factor, also called IGF-1Ec) is a peptide active ingredient and a naturally occurring splice variant of insulin-like growth factor 1 (IGF-1) that is locally expressed in tissue after mechanical load or muscle damage. In preclinical studies, its E-peptide activates muscle progenitor cells and supports regeneration; no controlled clinical trials with exogenous MGF in humans have been published to date.
What is MGF?
MGF was first described in the early 2000s by Goldspink's group and arises from alternative splicing of the IGF-1 gene: while "classical" IGF-1Ea acts mainly systemically, IGF-1Ec/MGF is rapidly upregulated after stretch, contraction or injury and works predominantly locally in the damaged muscle. The C-terminal E-peptide is regarded as the main effector driving the satellite cell response.
How does MGF work?
- Satellite cell activation: In vitro, MGF-E increases proliferation of human muscle progenitor cells and delays their differentiation - even when the IGF-1 receptor is blocked.
- Local repair cascade: Via matrix metalloproteinases and fibrinolysis, the tissue environment is prepared for infiltrating progenitor cells.
- Cardioprotection in animal models: After experimental infarction in sheep, MGF improved hemodynamic parameters more than mature IGF-1.
- Stem cell mobilisation: Animal data suggest enhanced migration of bone-marrow-derived mesenchymal stem cells.
Systemic exposure remains minimal because of a serum half-life of only a few minutes, which is why a pegylated version (PEG-MGF) was developed for longer circulation.
Research & evidence
The evidence base rests on three main pillars:
- In vitro human cell data: Kandalla et al. (2011) showed that synthetic MGF-E peptide extended the proliferative lifespan of satellite cells from neonatal, young-adult and old-adult donors, with reduced responsiveness in old cells.
- Animal muscle models: Mouse and rat studies report reduced inflammatory markers and improved regeneration after experimental muscle lesion.
- Animal cardiac models: Intracoronary MGF after ischemia reduced infarct size in sheep.
Critical voices also exist: one independent lab failed to show any effect of synthetic MGF-E peptide on myoblasts or primary muscle stem cells, directly contradicting the core mechanistic claims. To our knowledge, no randomised controlled human trial of exogenous MGF has been published.
MGF vs. PEG-MGF
- MGF (native sequence): corresponds to the human IGF-1Ec splice variant; half-life only minutes, which limits clinical translation.
- PEG-MGF: pegylated variant with longer circulation time; the most commonly used construct in the research literature.
Safety & regulatory status
- No marketing authorisation for MGF or PEG-MGF in the EU, US, Switzerland or UK.
- No clinically validated human dose - any dosing would be purely experimental.
- Anti-doping status: MGF is on the WADA Prohibited List (S2.2 - growth factors) and is banned in sport.
- Quality risk: products from unregulated sources are frequently underdosed, misfolded or contaminated with peptides of similar sequence.
Frequently asked questions about MGF
Is MGF the same as IGF-1?
No - MGF is a splice variant of the same gene, making it a related but distinct peptide active ingredient with different kinetics and tissue distribution.
Does MGF work in humans?
No controlled clinical trial demonstrates efficacy of exogenously administered MGF in humans. Preclinical data are mechanistically interesting but insufficient for efficacy claims in people.
How is MGF stored and prepared?
Lyophilised MGF is kept refrigerated (2-8 °C), reconstituted MGF belongs in the freezer. Step-by-step reconstitution instructions are available in the Peptipedia guides, and to estimate your syringe volume use the Reverse Dose Calculator. For the full toolkit see Tools.
Is MGF legal?
It is not approved as a medicine in any Western jurisdiction. Possession and purchase rules vary by country; in sport it is prohibited under the WADA list.
This article is for information only and does not replace medical advice or an individual diagnosis. Peptipedia does not recommend any dose, source or use.
Related peptides
Sources
- Preferential expression of IGF-1Ec (MGF) transcript in cancerous tissues of human prostate: evidence for a novel and autonomous growth factor activity of MGF E peptide in human prostate cancer cells (Armakolas A et al., Prostate 2010)
- Expression of IGF-1 isoforms after exercise-induced muscle damage in humans: characterization of the MGF E peptide actions in vitro (Philippou A et al., In Vivo 2009)
- 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 (Kandalla PK et al., Mech Ageing Dev 2011)