Gathering the record
Relay is organizing the evidence and source boundaries.
IGF-1 splice-variant research peptide
MGF is a name used for a mechano-responsive IGF-1 splice variant and its E-peptide. Most outcome claims come from cells or animals, not human administration studies.
60-Second Overview
Start with what it is, why it matters, what research has shown, and what remains unknown. The science follows after the orientation.
Start here. These four answers explain why the compound matters before the page introduces the deeper science.
Mechano growth factor, or MGF, is a name used for a muscle-responsive version of the IGF-1 gene message and for synthetic fragments derived from it.
Researchers study how muscle changes its growth-factor messages after mechanical stress and whether related fragments affect repair signals in cells or animals. Those questions are different from administering a commercial peptide to people.
Human studies located by Relay measured the body's own IGF-1 splice-variant expression after exercise. Laboratory and animal work has explored synthetic fragments, but no controlled administered-human outcome trial established muscle growth, injury recovery, or clinical benefit.
The identity of marketed material, human exposure, absorption, immune reactions, effective concentration, repeated-use safety, and meaningful outcomes remain unresolved. Endogenous gene expression cannot supply an exogenous amount, route, or preparation process.
The research depth, routes, studies, and primary sources below explain how Relay knows—and where the evidence stops.
Research context
Published research has investigated this compound using the following study designs.
These records explain what researchers did. They are not instructions, recommendations, or a transferable protocol.
The human study record measured natural IGF-1 splice-variant expression after resistance exercise; participants were not given synthetic MGF.
Reported study administration—not a recommendation.
Research at a glance
Evidence depth, confidence, and route context explain how Relay knows—not what anyone should do.
Preclinical and mechanistic; no controlled administered-human outcome evidence located.
Research depth describes how large and mature the overall record is. It does not tell you whether the results were positive.
Whether any defined exogenous MGF formulation produces reproducible, clinically meaningful human outcomes with acceptable safety.
Confidence describes how reliable and consistent the conclusions are. It can be high for one outcome and low for another.
The strongest evidence type shows what the best-supported conclusions are actually based on.
Human findings are more directly relevant than animal or laboratory results, but they still apply only to the populations and outcomes studied.
Route-specific record
These are exposures used in cited research for a specific route and population—not an instruction for an individual.
Half-life describes how long it takes the measured amount in the body to fall by half. It is not a dosing recommendation.
Evidence can change by administration method. Findings from one route should not automatically be applied to another.
Evidence boundary: Expression after exercise does not establish what an administered synthetic fragment does. No verified human route, pharmacokinetic program, efficacy trial, or product handling standard was located. Amounts shown describe cited research exposure—not a dosage recommendation.
Detailed evidence
Start with the strongest supported conclusion and its main uncertainty. Claim-level records below show how the evidence changes by question, population, route, formulation, and study design.
Human studies located by Relay describe exercise-related expression of IGF-1 splice variants, not clinical outcomes after administered MGF.
This is the strongest supported conclusion in the current human evidence—not a summary of every claim made about the compound.
Whether any defined exogenous MGF formulation produces reproducible, clinically meaningful human outcomes with acceptable safety.
Keeping the main uncertainty visible prevents an early or promising finding from looking more settled than it is.
Questions people bring to the evidence
Research questions—not promises of benefit.
This is the strongest human-evidence boundary in the current record.
Mechanistic findings explain biological plausibility; they do not establish a human outcome.
Relay keeps this uncertainty visible rather than converting it into a prediction.
The safety snapshot reflects the studied record and its limitations.
Regulatory and identity status determine how the evidence should be interpreted.
Mechanisms
Mechanical loading can alter IGF-1 transcript splicing, while synthetic MGF E-peptide experiments explore muscle and repair signaling. Endogenous-expression studies and exogenous peptide experiments are not interchangeable.
A plausible mechanism can explain why a study was attempted. It does not prove that the compound improves a human outcome.
Studies
Study arms are reported for transparency. They describe what researchers did in a defined record and do not transfer across identities, routes, formulations, or populations.
A later trial phase can ask a more mature question, but it does not guarantee a positive result, regulatory approval, or relevance outside the studied population.
Human muscle-biopsy expression study
Younger and older adults
Endpoints were not fully described in the current record.
Resistance exercise altered endogenous IGF-I splice-variant expression in sampled human muscle.
Study administration: Not stated in the current record.
Limitations: Expression does not establish outcomes from administering a synthetic MGF peptide.
Controlled animal injury study
Rats
Endpoints were not fully described in the current record.
A synthetic E-peptide was evaluated in an animal ligament-repair model.
Study administration: Not stated in the current record.
Limitations: Animal injury-model findings do not establish human efficacy or safety.
Narrative review
Population not stated.
Endpoints were not fully described in the current record.
The review describes a largely preclinical and mechanistic evidence base.
Study administration: Not stated in the current record.
Limitations: A review does not replace controlled human trials.
Safety snapshot
Human pharmacokinetics, dose-ranging, immunogenicity, and longer-term safety have not been established for an administered MGF product.
Other human evidenceReported events depend on population, formulation, route, exposure, comparator, and study size.
Open sourceThe current record does not support a reliable common-versus-uncommon frequency split.
Evidence boundaryUnder-detected or under-reported events must not be described as rare.
No source-qualified compound-specific warning or contraindication is encoded in the current record.
Evidence boundaryNo FDA-approved MGF product; human research identified by Relay measures endogenous expression rather than administered MGF efficacy. Whether any defined exogenous MGF formulation produces reproducible, clinically meaningful human outcomes with acceptable safety.
The current record does not identify a reliable compound-specific pattern of events that caused study discontinuation.
Evidence boundaryThis is an evidence gap, not proof that discontinuations did not occur.
No compound-specific patient-facing urgent-action threshold is established in the current Relay record.
Evidence boundaryRelay does not infer emergency guidance from study discontinuations, mechanism, or incomplete adverse-event reporting.
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PMID 18841527
PMID 30317597
PMID 36503467