PEG-MGF

Muscle Research only Animal studies

Also called Mechano Growth Factor, IGF-1Ec

A 24-amino-acid fragment from a splice variant of the IGF-1 gene that muscle produces after mechanical stress. A polyethylene glycol chain is attached to slow its breakdown. It is studied for activating satellite cells, the stem cells that repair and add muscle fibres.

Evidence at a glance

Evidence: Animal studies — Not yet studied in people
Status: Research compound only
Dosing: No human study has set a dose

Reviews note that no equivalent natural peptide has ever been isolated from cells, so the research material is synthetic and its physiological relevance is debated. No human trials.

What studies report

Activated muscle satellite cells in culture
Increased muscle fibre repair in rodent injury models
Behaves differently from mature IGF-1 in cell studies

How it works

A fragment of the IGF-1 splice variant muscle produces after mechanical stress. It is studied for activating satellite cells, the stem cells that repair damaged fibres. The PEG chain slows its clearance.

Binds a receptor on the cell surface and signals inward

Where it acts

Skeletal muscle

The library groups this compound under Muscle. The diagram shows that target, not every tissue it reaches.

Illustrated

A single skeletal muscle fibre with several peripheral nuclei beneath the membrane, lengthwise anatomical close-up.

AI-generated subject illustration; not a depiction of the compound or evidence of its effects.

Why people take it

Muscle repair after trainingSatellite cell activationRecovery from muscle injury

Reasons people seek it out — not a list of proven effects.

In practice Unapproved use

Used post-workout, sometimes injected into the muscle group trained

Reported real-world use, not evidence and not a recommendation.

Status: Research compound. Not approved.

Route: Subcutaneous injection, from reconstituted lyophilised powder
Available as: 5 mg

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Educational information only. Nothing here is medical advice, a dosing protocol, or a recommendation to use any compound. Most entries describe substances not approved for human use. Talk to a licensed clinician before acting on anything you read here. How to read these entries.