PEG-MGF

Key Benefits#

• Extended half-life (~3 days) vs native MGF (minutes)
• Systemic muscle satellite cell activation via subcutaneous injection
• Promotes muscle fiber repair and hypertrophy throughout the body
• Enhanced recovery from intense training or muscle injury
• Synergistic with IGF-1 LR3 and growth hormone peptides
• Useful in sarcopenia, post-injury recovery, and athletic performance
• Single injection provides multi-day anabolic signaling

Mechanism of Action#

MGF is a splice variant of IGF-1 produced in response to mechanical loading of muscle tissue. Its unique N-terminal peptide activates muscle stem cells (satellite cells), promoting their proliferation and differentiation into new muscle fibers. PEGylation prevents rapid enzymatic degradation and renal clearance, extending the half-life from ~minutes to ~3 days. This allows subcutaneous injection with systemic distribution to all muscle groups, activating satellite cells throughout the body for enhanced recovery and hypertrophy.

Dosing Protocols#

Side Effects#

• Water retention and localized swelling
• Potential hypoglycemia at high doses
• Theoretical cancer growth risk (growth factor)
• Injection site reactions
• Limited long-term human safety data

Contraindications#

Not FDA approved. Active malignancy is an absolute contraindication. Pregnancy contraindicated. Medical oversight required.

Storage#

Lyophilized: store at -20°C. Reconstituted: refrigerate at 2–8°C, stable up to 2 weeks.

1. 1.
   Dose optimization of PEG-rhGH therapy to improve growth outcomes of childhood-onset growth failure

   Wu Y, Zhang L, Ma H, Wang P, Lu M, Xv X et al. · Growth hormone & IGF research : official journal of the Growth Hormone Research Society and the International IGF Research Society · 2025PubMed Verified

2. 2.
   Bioresponsive release of insulin-like growth factor-I from its PEGylated conjugate

   Braun AC, Gutmann M, Mueller TD, Lühmann T, Meinel L · Journal of controlled release : official journal of the Controlled Release Society · 2018PubMed Verified

3. 3.
   First-in-man study with a novel PEGylated recombinant human insulin-like growth factor-I

   Kletzl H, Guenther A, Höflich A, Höflich C, Frystyk J, Staack RF et al. · Growth hormone & IGF research : official journal of the Growth Hormone Research Society and the International IGF Research Society · 2017RCTPubMed Verified

4. 4.
   The insulin-like growth factor I system: physiological and pathophysiological implication in cardiovascular diseases associated with metabolic syndrome

   Ren J, Anversa P · Biochemical pharmacology · 2015ReviewPubMed Verified