PEG-MGF

Growth factor · Also known as PEGylated Mechano Growth Factor

Muscle growth Recovery

What is PEG-MGF?

A PEGylated version of mechano growth factor that extends its half-life. MGF is a splice variant of IGF-1 produced in response to mechanical stress on muscle tissue.

PEG-MGF adds a polyethylene glycol molecule to MGF, extending its half-life from minutes to hours. MGF is naturally produced when muscles are damaged during exercise, recruiting satellite cells to repair and grow muscle fibers.

Key takeaway: PEG-MGF is an extended-release form of a muscle repair growth factor, but human clinical data remains very limited.

Benefits & evidence

Muscle repair Preliminary confidence

Satellite cell activation Preliminary confidence

How it works

When muscle tissue is mechanically stressed (exercise, injury), the IGF-1 gene is spliced differently to produce MGF. This local growth factor activates muscle satellite cells, the stem cells responsible for muscle repair and growth.

Native MGF degrades within minutes. The PEG modification protects it from enzymatic breakdown, allowing systemic administration rather than requiring local injection at the muscle site.

Dosing information

Typical dosing protocol

Starting dose

200 mcg

Post-workout

Maintenance dose

200-400 mcg

2-3x per week

Typically injected into the trained muscle group. Limited human dosing data available.

Side effects

Most side effects tend to improve as your body adjusts.

Injection site pain Common

Hypoglycemia Moderate

Research (4 studies)

Dose optimization of PEG-rhGH therapy to improve growth outcomes of childhood-onset growth failure. Growth hormone & IGF research : official journal of the Growth Hormone Research Society and the International IGF Research Society · 2025

Bioresponsive release of insulin-like growth factor-I from its PEGylated conjugate. Journal of controlled release : official journal of the Controlled Release Society · 2018

First-in-man study with a novel PEGylated recombinant human insulin-like growth factor-I. Growth hormone & IGF research : official journal of the Growth Hormone Research Society and the International IGF Research Society · 2017

The insulin-like growth factor I system: physiological and pathophysiological implication in cardiovascular diseases associated with metabolic syndrome. Biochemical pharmacology · 2015

Quick summary

Type PEGylated growth factor

Best for Muscle repair

Administration Intramuscular

Frequency 2-3x per week

Risk level Moderate

FDA status Not approved

Evidence Preliminary