Scientific context only. Not medical advice, not a recommendation to use.
At a glance
Synthetic peptide corresponding to the C-terminal E-domain of the IGF-1 splice variant IGF-1Ec. Described in preclinical studies as a 'mechano-induced' skeletal muscle repair factor. No marketing approval; clinical use largely confined to the black market.
Researched for
Muscle satellite cell activation in animal modelsMuscle regeneration after injury (preclinical)Theoretical application in sarcopenia
Official status
US: Unapproved
No FDA approval. On the WADA prohibited list under S2 as a growth factor.
The IGF-1 gene produces multiple isoforms by alternative splicing. IGF-1Ec is upregulated after mechanical muscle loading; the C-terminal E-domain is cleaved from the mature IGF-1 protein and appears to have independent effects on satellite cells. The exact receptor binding of the E-domain is not established; a classical IGF-1R effect is unlikely since mature IGF-1 is responsible. In cell-culture studies, stimulation of myoblast proliferation and differentiation has been observed.
02
Evidence at a glance
Reading note. The distribution shows on which evidence tier each observation sits. Strong colours mark stronger evidence — weaker tiers are deliberately visible, not hidden.
3 observations · 3 tiers
Animal model
1
In vitro
1
Theoretical
1
03
What the studies show
In vitro
Myoblasten-Kultur
Yang S. et al. 2002
Activation of muscle satellite cells and enhanced myoblast proliferation documented in cell-culture studies
What does NOT follow: In-vitro finding; translation to intact muscle is limited by the extreme brevity of the plasma half-life.
Animal model
Maus
Improved muscle regeneration after injury observed in mouse models with local intramuscular injection
What does NOT follow: Effect observed locally with direct injection into the injured muscle — not comparable to systemic subcutaneous use.
Theoretical
—
Clinical human endpoint data (muscle mass, function, rehabilitation outcomes) is virtually non-existent
What does NOT follow: There are no published controlled human trials for sport or rehabilitation endpoints. Frequently cited bodybuilding claims rely on animal and cell findings.
05
Pharmacokinetics
Theoretical concentration curve at a half-life of 0.1 h. Pure pharmacokinetic model — not a dosing recommendation.
Which routes of administration the available studies describe — neutral reporting, not a usage guide.
Intramuscular
In the preclinical animal models injected locally intramuscularly into the injured muscle.
Subcutaneous
Black-market use predominantly subcutaneous — follows conventions of other peptides without clinical-study basis for this route.
07
Known adverse events from studies
Factual reporting of what studies observed. Not a safety statement for individual use.
Theoretical
Human pharmacovigilance practically non-existent
Safety profile under systemic use outside preclinical models is not established. IGF axis activation carries theoretical mitogenic risk.
07b
Interactions & combinations
Documented interactions and contraindications from studies, prescribing information and guidelines. Where no data exists, this is stated.
Reporting of risks, NOT a combination guide. The absence of an entry does not mean „safe to combine“ but „not sufficiently studied“.
No documented interactions recorded
We have not yet found robustly documented interactions for this peptide. This does NOT mean none exist — the data is limited.
08
Risks & hygiene aspects in the literature
What regulatory and scientific literature reports on risks, sterility and identity in non-pharmaceutical sources — descriptive, not a hygiene guide.
Identity and purity problem
What is sold on the black market as 'MGF' is not standardised. Investigations have documented that products often contain IGF-1, IGF-1 LR3 or mixtures — not the declared peptide.
10
Anecdotal observations
Weakest evidence tier — not supported by studies
Reading note. This section gathers popular claims from communities and forums. They are explicitly marked as weakest-tier evidence. Unblinded self-reports are particularly prone to placebo, recall and confirmation biases.
Why no amounts or protocols are listed here. We deliberately show only WHAT communities report — not in what amount or how it is used. Anecdotal "doses" or "biohacker protocols" are neither verified nor standardised nor safe; publishing them would be a usage guide, which we do not provide on principle. Specific amounts belong in a conversation with a doctor, not in a forum.
In bodybuilding forums MGF is described as a 'local muscle-building factor' — supposedly for hyperplasia rather than hypertrophy.
common, often compared to IGF-1 LR3
Not supported by studies: The hyperplasia claim is mechanistically speculative. Direct comparisons with IGF-1 LR3 are not supported by controlled human trials. The extremely short plasma half-life makes systemic use pharmacologically implausible.
11
Legal status by country
Country
Status
Note
Checked
United States
Unapproved
No FDA approval. On the WADA prohibited list under S2 as a growth factor.
2026-05-22
Germany
Unapproved
No EMA approval. Sale as a 'research chemical' is not legally covered; WADA-prohibited.
2026-05-22
Australia
Banned
TGA status: SUSMP Schedule 4. WADA-prohibited.
2026-05-22
12
Reconstitution calculator
Pure mg/mL maths — works like a calculator. Not a usage recommendation.
Peptides ship as a dry powder. Once dissolved in a liquid (reconstitution), this calculator answers a single question: how much substance is in one millilitre of solution afterwards?
1Enter the vial's substance amount (printed on the label).
2Enter how much solvent you add.
3Result = concentration in mg per mL.
Printed on the label
/
Liquid you add
=
2.50
mg / mL
5 mg in 2 mL gives 2.50 mg/mL — each millilitre contains 2.50 mg of substance.