MGF (Mechano Growth Factor): what it is and what the evidence says
A splice variant of the IGF-1 gene that muscle itself produces after intense mechanical loading. It is an endogenous repair signal, not a designed product.
Last reviewed: August 16, 2026 · How we verify this
The ground it plays on
Tissue repair happens in phases, not all at once: an initial inflammation that is actually useful, the building of new tissue, and then its remodeling, which can take months. Compounds studied in this area relate to one of those phases. None of them replaces rest or rehabilitation, and that is precisely the most common mistake people make when reading about them.
What it is studied for
Advertised for muscle repair and growth.
There is a distinction that almost always gets lost. A compound being studied for something is not the same as achieving it. And even where it works in a dish or in a mouse, that says little about whether it works in a person or whether the benefit is worth the risk. The section below therefore carries more weight than everything above it.
What the human evidence says
In people, skeletal muscle has been shown to express the IGF-1Ec isoform (MGF) naturally, and that expression rises after intense resistance exercise, with a smaller response in older adults. There are no published trials yet in which the synthetic peptide is given to people.
The limitation that matters most
What remains to be shown in people is that giving the peptide reproduces the role of the natural isoform. The effects on myoblasts and satellite cells come from cell cultures and rodents and differ between labs: several studies observed them and one from 2014 found no apparent effect. Its receptor and its long-term safety are also unknown.
Regulatory status
It is not approved as a medicine by any agency and has not entered clinical trials. On the FDA's 503A list (updated May 2026) it sits in category 3, substances nominated without adequate supporting documentation. In sport, WADA prohibits it at all times under section S2.3 (mechano growth factors).
Status can change and varies by country. Always verify the rules in force where you live before drawing conclusions.
Cautions and context
It has never been given to people in a trial. Banned in sport.
With a history of cancer, pregnancy or breastfeeding, an undiagnosed injury, or if you compete under anti-doping control, have a professional assess it before you start.
What this page cannot give you
A reference page can take you this far. You know what MGF (Mechano Growth Factor) is and where its research stands, which already puts you ahead of most readers. Four questions remain that no encyclopedia can answer for you, because the answers depend on your own situation:
- What would you measure beforehand, so that later you could tell whether anything actually changed?
- What would you watch along the way, and how consistently?
- What would you ask a professional, and in how much detail, so you do not walk out with a textbook answer?
- What would make you stop?
That is what the course is for
PeptiXtreme is ${CIF.LECCIONES} lessons that hand out no numbers. Each one ends with your starting point, what to watch along the way, the specific questions you take to a professional and the signals that mean stop. It includes per-module exams, a Certificate of Completion with a verifiable certificate ID, a Progress Tracker to follow how you are doing, and a human advisor you can actually write to.
See the course → Or measure your judgment, freeReferences
Every entry links to its record on PubMed, the US National Library of Medicine database. Open them and check. We would rather have a reader who verifies than one who takes our word for it.
- Expression of IGF-I splice variants in young and old human skeletal muscle after high resistance exercisehuman J Physiol · 2003 · PMID 12562960 →
- Expression of IGF-1 isoforms after exercise-induced muscle damage in humans: characterization of the MGF E peptide actions in vitrohuman In Vivo · 2009 · PMID 19567392 →
- Different roles of the IGF-I Ec peptide (MGF) and mature IGF-I in myoblast proliferation and differentiationpreclinical FEBS Lett · 2002 · PMID 12095637 →
- 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 agespreclinical Mech Ageing Dev · 2011 · PMID 21354439 →
- Mechano-growth factor peptide, the COOH terminus of unprocessed insulin-like growth factor 1, has no apparent effect on myoblasts or primary muscle stem cellspreclinical Am J Physiol Endocrinol Metab · 2014 · PMID 24253050 →
- Mechano-Growth Factor: an important cog or a loose screw in the repair machinery?review Front Endocrinol (Lausanne) · 2012 · PMID 23125840 →
- Minireview: Mechano-growth factor: a putative product of IGF-I gene expression involved in tissue repair and regenerationreview Endocrinology · 2010 · PMID 20130113 →
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Frequently asked questions
What is MGF (Mechano Growth Factor)?
A splice variant of the IGF-1 gene that muscle itself produces after intense mechanical loading. It is an endogenous repair signal, not a designed product. It is studied within the area of regenerative.
Is there human evidence for MGF (Mechano Growth Factor)?
In people, skeletal muscle has been shown to express the IGF-1Ec isoform (MGF) naturally, and that expression rises after intense resistance exercise, with a smaller response in older adults. There are no published trials yet in which the synthetic peptide is given to people.
Is it approved by any health agency?
It is not approved as a medicine by any agency and has not entered clinical trials. On the FDA's 503A list (updated May 2026) it sits in category 3, substances nominated without adequate supporting documentation. In sport, WADA prohibits it at all times under section S2.3 (mechano growth factors).
What is the dose of MGF (Mechano Growth Factor)?
We do not publish dosages. This is not an oversight. No single figure works for everyone: the regimen depends on a person's medical history, on whatever medication they already take, and on the goal they are chasing, which is something a professional weighs with the case in front of them. What you can build is the ability to walk into that appointment knowing what to ask.
Where can I learn to evaluate this properly?
This page tells you what MGF (Mechano Growth Factor) is and what the evidence says. The PeptiXtreme course teaches the other half: what you would measure before considering anything, what you would watch, the specific questions you would take to a professional and when you would stop.