MGF
Mechano Growth Factor (IGF-1 Ec/Eb splice variant peptide)
Mechanism of Action
Alternative splice product of the IGF-1 gene, transcribed preferentially in mechanically loaded or damaged skeletal muscle. Activates quiescent satellite cells (MyoD upregulation) to re-enter the cell cycle within hours of tissue damage, ahead of the later, slower rise in systemic IGF-1Ea that drives differentiation and hypertrophy.
Key Benefits
- Rapid satellite cell activation after training damage (preclinical)
- Early-phase muscle repair signaling
- Complements the later systemic IGF-1Ea hypertrophy phase
Dosing Protocol
Extremely short-acting — injected immediately post-workout, localized near the trained muscle group, to align with the natural post-damage expression window. PEG-MGF was developed specifically to work around this short half-life.
Ideal Candidates
Advanced users targeting acute post-training muscle repair; requires precise post-workout timing given its extremely short half-life.
Side Effects & Safety
Injection site reactions; theoretical growth-factor risks shared with the broader IGF-1 axis; aging tissue shows a blunted MGF response, so effects may be attenuated in older users (per preclinical data).
Regulatory Status
RestrictedResearch compound only. No 503A bulks list. Limited human data; synthetic peptide corresponds to a splice-variant fragment, not full-length IGF-1.
Evidence & Citations
- Hill M, Goldspink G. 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. J Physiol. 2003;549(Pt 2):409-18.
- Owino V, Yang SY, Goldspink G. Age-related loss of skeletal muscle function and the inability to express the autocrine form of insulin-like growth factor-1 (MGF) in response to mechanical overload. FEBS Lett. 2001;505(2):259-63.
- Matheny RW, Nindl BC, Adamo ML. Minireview: Mechano-growth factor: a putative product of IGF-I gene expression involved in tissue repair and regeneration. Endocrinology. 2010;151(3):865-75.
Frequently asked
What is MGF?+
MGF (Mechano Growth Factor (IGF-1 Ec/Eb splice variant peptide)) is a peptide studied for igf-1 splice variant and satellite cell activation. Alternative splice product of the IGF-1 gene, transcribed preferentially in mechanically loaded or damaged skeletal muscle. Activates quiescent satellite cells (MyoD upregulation) to re-enter the cell cycle within hours of tissue damage, ahead of the later, slower rise in systemic IGF-1Ea that drives differentiation and hypertrophy.
What is the dosing protocol for MGF?+
Literature commonly references 200 mcg (per site) (low) to 400 mcg (per site) (maintenance) via SubQ / IM, localized to trained muscle, on a 4–6 weeks cycle. Educational reference only — a licensed Stackhaus Health provider sets any personalized protocol.
What is the regulatory status of MGF?+
Research compound only. No 503A bulks list. Limited human data; synthetic peptide corresponds to a splice-variant fragment, not full-length IGF-1.
Where can I access MGF?+
Research-grade MGF is available through Stackhaus Research. For a personalized, provider-reviewed protocol, consult a licensed clinician through Stackhaus Health.