Reviewed & approved by Dr. Nova Reyes · Last checked 2026-10-25. ← Back to Evidence Library
MGF / PEG-MGF (mechano growth factor): what the evidence says
At a glance
MGF and PEG-MGF have no published human trials. Unknown
What it is: MGF is a splice variant of IGF-1 made in muscle after strain. Vendors sell a short synthetic "E-domain" peptide (sometimes PEGylated to last longer) under this name. R1, R2
What the evidence says: lab and animal studies only, mostly heart-attack and cell models. One lab study found the commonly sold short MGF peptides did not activate the IGF-1 receptor at all. R2, R3
Biggest risks: unknown in humans. Unknown
Rating
| Human Human evidence | No human data |
| Animal Animal / lab evidence | Cell and rodent studies; mixed R1–R3 |
| Regulatory | Not FDA-approved (no Drugs@FDA record) · Not approved anywhere in the world · WADA 2026: prohibited at all times (S2.3, "Mechano growth factors (MGFs)" named) R5 |
| Established human dose | None. Never studied in people |
Evidence verdict: Human: No human data · Animal/lab: mixed Card verdict: No human data (muscle-repair claims rest on animal and cell studies only)
This page reports what studies used. It is not dosing advice.
Legend: HUMAN data · ANIMAL / LAB data · UNKNOWN · UNVERIFIED: not yet confirmed against a primary source
What is it?
Mechano growth factor (IGF-1Ec in humans) was described by Goldspink's group. Whether it has a distinct role from IGF-1 is debated. R1
Does it work?
- Animal Receptor test: full-length MGF activated the IGF-1 receptor, but the short "human MGF" and "Goldspink-MGF" peptides showed no IGF-1 receptor activation. R2
- Animal Heart (rodents): an E-domain peptide preserved heart function after induced heart attacks. R3
- Unknown Muscle growth in people: vendor and forum claims only.
Is it safe?
- Unknown No human safety data.
Gray-market "research use only" MGF / PEG-MGF (mechano growth factor): extra risks
Unknown contents. Products sold online as "research use only" or "not for human use" are not made under drug-quality rules, so identity, strength and sterility are unknown. This is a general caution; we have not found testing data for this product specifically. Unknown
Doping tests. Anti-doping labs have built tests for MGF. R4
What we don't know
- Unknown Any effect in people
- Unknown What vendor "MGF" and "PEG-MGF" actually contain
Is it legal?
Not FDA-approved (no Drugs@FDA record, openFDA query Oct 24, 2026) and not approved anywhere in the world. WADA: prohibited at all times under S2.3 (growth factors), which names "Mechano growth factors (MGFs)"; S2 substances are non-Specified R5.
Study details
These are doses researchers used, not recommendations.
R1–R4 Animal Lab / animal
| Study | People / model | Route | Dose used | Follow-up | Reported | Side effects / dropouts | Citation |
|---|---|---|---|---|---|---|---|
| Zabłocka 2012 (review) | — | — | — | — | Debate on MGF role | — | PMID 23125840 |
| Janssen 2016 | Receptor assays | Lab | — | — | Full-length MGF activates IGF-1R; short MGF peptides do not | — | PMID 26991004 |
| 2013 E-domain study | Rodent heart attack model | Injection | See paper | Not in abstract | Less apoptosis, preserved heart function | Not in abstract | PMID 23712705 |
| 2014 doping-control method | — | — | — | — | Mass-spec detection of full-length MGF | — | PMID 25466910 |
Full reference list (PubMed entries verified Oct 24, 2026)
- R1 Zabłocka B, et al. Front Endocrinol. 2012;3:131. PMID 23125840
- R2 Janssen JA, et al. PLoS One. 2016;11(3):e0150453. PMID 26991004
- R3 The E-domain region of mechano-growth factor inhibits cellular apoptosis and preserves cardiac function during myocardial infarction. Mol Cell Biochem. 2013. PMID 23712705
- R4 Mass spectrometric characterization of a biotechnologically produced full-length MGF relevant for doping controls. Growth Horm IGF Res. 2014. PMID 25466910
- R5 WADA. World Anti-Doping Code International Standard: Prohibited List 2026 (in force Jan 1, 2026). https://www.wada-ama.org/sites/default/files/2025-09/2026list_en_final_clean_september_2025.pdf (text read Oct 24, 2026)
Disclaimer
This page summarizes published research for education and harm reduction; it is not medical advice or a recommendation to use MGF or PEG-MGF. Talk to a clinician you trust before using any drug, and report side effects to FDA MedWatch.
Approved for Adam Greene by Dr. Nova Reyes, 2026-10-25.