Gathering the record
Relay is organizing the evidence and source boundaries.
IGF-1 splice-variant research peptide
A name used for the body's muscle-related growth signals and for experimental peptides based on them.
Evidence is explained by question. Dosing references show their own check dates.
60-second overview
Why people look into it, what studies found, and what is still unknown.
Educational information only. Evidence reviewed through July 31, 2026. Published studies, sponsor announcements, and trials without results are labeled separately. Evidence gaps apply to the specific finding beside them.
Research questions
Each label shows how much evidence supports that question.
What studies show
Human studies located by Relay describe exercise-related expression of IGF-1 splice variants, not clinical outcomes after administered MGF.
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.
Risks & unknowns
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 available information does not reliably show how often particular side effects occur.
Evidence boundaryUnder-detected or under-reported events must not be described as rare.
Relay has not verified which side effects led people to stop treatment in studies.
Evidence boundaryThis is an evidence gap, not proof that discontinuations did not occur.
Relay has not verified a compound-specific warning summary for this profile.
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.
This profile does not contain verified, product-specific emergency instructions.
Evidence boundaryRelay does not infer emergency guidance from study discontinuations, mechanism, or incomplete adverse-event reporting.
Dosing references
Each table labels its source and applies only to the named route, product, or study. An online example or community report is not an approved dose.
MGF can mean an IGF-1 splice product or a synthetic E-domain fragment. Exercise-related expression studies do not establish an injected fragment's dose.
What would fill this gap: A sequence-defined synthetic product and a direct human administration source.
Dosing review checked Oct 20, 2026. Additional sources are available below.No route-specific preparation instructions were verified. A different route or product does not supply them.
Starting dose: the amount used at the beginning of the named label schedule or trial.
Maintenance: the ongoing amount described by that product label.
Trial target: the amount assigned to a study group. Different groups may stop increasing at different targets.
The human study record measured natural IGF-1 splice-variant expression after resistance exercise; participants were not given synthetic MGF.
Population: Younger and older adults
Design: Human muscle-biopsy expression study
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.
Research reference
A reference for the studies, populations, and routes behind this profile.
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.
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.
Community
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Every structured report adds useful context about research setup, outcomes, and unwanted effects as the community dataset grows.
Publicly anonymous by default. Your account keeps reports editable and helps reduce duplicate submissions.Sources
PMID 18841527
PMID 30317597
PMID 36503467