PEG-MGF

Areas of active research — not promised effects

Each tag links to other compounds with research into that goal. Research use only: these are areas of study, not human-use claims.

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PEG-MGF has no FDA-approved drug application (NDA or BLA) and cannot be lawfully prescribed or administered to humans. It was previously listed on the FDA 503A Category 2 bulk drug substances list, which effectively prohibited its use in compounding. As of April 23, 2026, the FDA's Category 2 list was restructured and PEG-MGF is no longer formally on Category 2; however, removal from Category 2 does not place it on the 503A Bulks List or authorize compounding — it exists in a regulatory gray zone pending formal PCAC advisory review.

Transparent blend · bci-1.0 · never paid-placement

Primary name

PEG-MGF

Origin

PEG-MGF is a synthetic conjugate of Mechano Growth Factor (MGF), itself the unique 24-amino-acid C-terminal E-peptide derived from the human IGF-1Ec splice variant produced by alternative splicing of exons 4–6 of the IGF1 gene. MGF is expressed endogenously in skeletal muscle in response to mechanical loading or tissue damage and acts as a local paracrine factor. The native peptide is extremely unstable in circulation, with a half-life measured in minutes, which limits its utility as a research tool. PEGylation — covalent attachment of polyethylene glycol chains — is a standard pharmaceutical strategy that shields the peptide from proteolytic enzymes and reduces renal clearance, extending the circulating half-life to approximately 48–72 hours. PEG-MGF has no approved therapeutic indication in any jurisdiction and is classified as a research-use-only (RUO) reagent. Its registry identity (CAS, PubChem CID, canonical sequence) remains unconfirmed in public databases; identity status is manual_pending.

Appearance

White to off-white lyophilized powder (vendor-typical for PEGylated peptides)

Solubility

Soluble in sterile water or bacteriostatic water; PEG conjugation generally impr…

Sequence not available in current seed.

Stability: PEGylation provides greater protease resistance than native MGF; however, the peptide core remains susceptible to chemical degradation under elevated temperatur

Vial sizes

2 mg · 5 mg

Purity grades

≥95% HPLC / ≥98% HPLC

Salt forms

Free base (primary)

• GHS hazard class on file
• PPE & spill response
• Disposal guidance
• Not-for-human-consumption posture

How much research exists, and of what maturity — never a verdict on whether it works.

Mechanism of action

• The biological activity of PEG-MGF is attributed to its MGF E-peptide core, which activates quiescent muscle satellite cells (muscle stem cells) via a mechanism distinct from, and complementary to, canonical IGF-1 receptor (IGF-1R) signaling
• The E-domain peptide engages satellite cells and drives them from the quiescent G0 phase into active proliferation without simultaneously triggering terminal differentiation, thereby expanding the progenitor pool available for subsequent muscle repair and regeneration
• In contrast, the separate mature IGF-1 domain of the IGF-1 precursor signals through IGF-1R to activate the PI3K/AKT/mTOR and MAPK/ERK1-2 cascades, promoting protein synthesis and differentiated cell growth
• PEGylation alters the pharmacokinetic profile without altering the E-peptide's intrinsic receptor-engagement mechanism, converting the molecule from a locally-acting autocrine/paracrine signal into a systemically circulating growth factor capable of reaching satellite cells in multiple muscle groups after a single subcutaneous administration

Pharmacokinetics (ADME)

Half-life

~48–72 hours (estimated for PEG-MGF); native MGF ~5–7 minutes in circulation

Clearance

Proteolytic and renal clearance are both reduced by PEG conjugation; specific clearance rate data from controlled PK studies are not available in the published literature as of data capture

PK–PD note: PK estimates are derived from vendor/reference characterization data and extrapolated from the general PEGylation pharmacology literature, not from published controlled PK trials in animals or humans.…

Reading the evidence

• Evidence quality and gaps vary by application — see the cited grades above.
• Indexed-article counts span all evidence tiers, not only completed human trials.
• No first-party human-dosing, efficacy, or benefit claims are made here.

Key reviews & evidence-gap sources

• Zabłocka et al. (2012) Mechano-Growth Factor: an important cog or a loose screw in the repair machinery? Front Endocrinol (Lausanne). 3:131. PMID: 23125840 — Editorial review covering IGF-1 isoform splicing, MGF E-domain biology, and satellite cell activation. Anchoring review for MGF mechanism.
• Matheny et al. (2010) Minireview: Mechano-growth factor: a putative product of IGF-I gene expression involved in tissue repair and regeneration. Endocrinology. 151(3):865-75. PMID: 20130113 — Comprehensive minireview on MGF as IGF-1 splice variant in tissue repair.
• Vassilakos et al. (2014) Biological activity of the E domain of the IGF-1Ec as addressed by synthetic peptides. Hormones (Athens). 13(2):182-96. PMID: 24776619 — Review of synthetic MGF E-domain peptide biological activity.
• Liu et al. (2023) The role of mechano growth factor in chondrocytes and cartilage defects: a concise review. Acta Biochim Biophys Sin. 55(5):701-712. PMID: 37171185 — Recent concise review on MGF in chondrocytes and cartilage.

1 registered trial — 0 currently recruiting.

Phase 2
NCT02375620
Clinical Study of Pegylated Somatropin (PEG Somatropin) to Treat SGA Children With Short Stature

ACTIVE_NOT_RECRUITING

Summary (literature)

No controlled human safety data exist for PEG-MGF. The compound has no approved clinical use, no registered human clinical trials attributed specifically to it, and no published human dose-finding or safety studies identified as of data capture. Anticipated risks are extrapolated…

WADA status

Prohibited — WADA 2026 Prohibited List Section S2.3 (Growth Factors and Growth Factor Modulators). Mechano Growth Factors (MGFs) are explicitly listed as prohib…

Dominant research route: Intramuscular (IM)

Manufacturer product monograph reports single-dose PK in 'healthy male and female adults' (extent of absorption 292 hr·g/L, peak concentration 37 g/L, Vd 14 L/kg); aggregator references also list SC as a studied route in animals

Bioavailability: Cooper Pharma monograph reports SC absorption extent 292 hr·g/L and Cmax 37 g/L after a single SC dose in healthy adults; PEGylation extends half-life from minutes (native MGF) to several hours, enabling systemic distribution

Layer A (cited PK) but flagged: the manufacturer-reported human PK data conflicts with the broader consensus (PeptideInsight, GLPbase) that PEG-MGF has not entered human clinical trials. Treat the human PK figures as unverified/contradictory until a primary study is located.

Rodent models (eccentric exercise-induced injury, cardiotoxin injection) — IM injection into target muscle increased Pax7-positive satellite cells and Ki67-positive proliferating cells at 24–72 h; native MGF E-peptide studies use IM injection (200–500 mcg/kg) because systemic injection degrades peptide before reaching target tissue

Bioavailability: IM administration produces local tissue responses consistent with growth factor activity; PEGylation permits less frequent dosing than native MGF but IM remains the dominant preclinical route for localized satellite-cell activation

Most preclinical efficacy evidence is via IM injection into the target muscle group; PEG-MGF IM is also referenced in community/research-chemical protocols (Layer B) but the cited biological data are animal/in vitro.

Listed as a route studied in animals (aggregator reference); no primary PK study retrieved

Bioavailability: No quantitative PK values retrieved for IP route; included only as a route referenced in preclinical animal work

Sourced solely from an aggregator's summary of routes studied in animals; no primary citation located within budget.

Animal & human figures are kept visibly separate so studied animal doses are never misread as human guidance.

Sorted A–Z by vendor — never by price

Weekly median $/mg from the live vendor crawl.

Researched storefront prices, bucketed

p25 $13.82 · median $18.24 · p75 $19.12 · 6 researched vendors

Legit, COA-backed band: $12.60–$20.00/mg.

Value rule: don't just buy the cheapest — a price under $3/mg is a red flag. Pair price with COA and independent-test grade.

Estimated cost of research (10 mg)

Vial (best researched price)

$118

Bacteriostatic water (generic estimate)

$6

Syringes / supplies (generic estimate)

$12

What each test proves — general guidance, plus this compound's researched purity data

Purity on the current market (researched)

Vendor-claimed purity ranges from ≥98% to 99.3% (e.g., Cooper Pharma states ≥98%, Montreal Peptides states 99.3%, PeptideDeck/Ascension states ≥98%). These are supplier self-reported COA values, not independently verified third-party results for PEG-MGF specifically.

Independent labs cited for this compound

No FDA recalls, market withdrawals, or safety alerts specific to PEG-MGF were found in the FDA enforcement databases reviewed. None found.

Buyer red-flag checklist

• Not FDA-approved for any indication; no NDA/BLA has been submitted or approved.
• Removed from FDA Category 2 (April 2026) due to nomination withdrawal, but NOT placed on Category 1 — remains in regulatory limbo, not eligible for lawful compounding under interim enforcement discretion.
• Prohibited at all times under WADA S2 (Peptide Hormones, Growth Factors, Related Substances and Mimetics).
• No independently verified third-party purity/identity test results for PEG-MGF were publicly retrievable; vendor COAs are self-reported and unverified.
• Gray-market risk of products being underdosed or not actually pegylated (suspiciously low pricing under ~$25/2mg flagged as indicator of underdosing or non-pegylated product).
• Subject to FDA Import Alert 66-41 (DWPE for unapproved new drugs) when imported.

GMP vs research-grade: the chemistry (SPPS + HPLC + MS) is identical — the difference is the quality system.

Underdosing / mislabeling: No PEG-MGF-specific independent lab test results (Janoshik, MZ Biolabs, Finnrick) were publicly retrievable for this compound at time of research. The Janoshik public tests portal (public.janoshik.com) was inaccessible (HTTP 403). General gray-market peptide testing aggregates indicate a substantial fraction of unverified peptide products do not match label claims, but no compound-specific prevalence figure for PEG-MGF could be sourced.

• Import Alert 66-41 — 'Detention Without Physical Examination of Unapproved New Drugs Promoted In The U.S.' PEG-MGF, as an unapproved new drug not on the 503A Category 1 bulks list and not FDA-approved, falls within the scope of this DWPE alert. The alert is not compound-specific to PEG-MGF but applies broadly to unapproved new drug products.66-41
• An RUO label is not an import exemption — CBP judges actual intended use.
• Lyophilized powder is ambient-stable in transit; temperature control needed for > 7-day transit.
• US-warehouse vendors dodge import scrutiny — they cost more but ship more reliably.

Every item dated & sourced

Prohibited at all times (in- and out-of-competition) under WADA Prohibited List category S2.3 (Growth Factors and Growth Modulators). The 2026 Prohibited List explicitly names 'Mechano growth factors (MGFs)' under S2.3. PEG-MGF, as a pegylated derivative of MGF, is covered by the same prohibition.

No granted patents identified in current seed. Composition-of-matter coverage is limited given the peptide's synthetic origin.

• IACUC / IRB research context
• RUO buyer responsibilities & documentation
• Veterinary / alternative-use where lawful
• Jurisdiction-aware "who may lawfully obtain"

What people discuss

Reported concerns — discussion, not established effects

Reading caveats

• Anecdotal self-experimentation without controls
• Bodybuilding-forum selection bias toward performance users
• Vendor-affiliated / affiliate-linked content present
• No registered human clinical trials for PEG-MGF; claims extrapolated from animal/cell models
• Survivorship bias — negative outcomes underreported

Manually researched from reddit, youtube, x— theme weights are research estimates, not live counts; aggregated & de-identified. No individual posts, quotes, or usernames are ever shown.

Relative research / market volume — populated once the activity stream is wired

Inline tooltips for lyophilized, RUO, EU/mg, SPPS, 503A and more.

Toggle plain-language ↔ scientific in the header.

• How to read a COA
• Free base vs acetate
• Understanding evidence grades

PEGylated synthetic analog of Mechano Growth Factor (IGF-1Ec E-peptide) studied for satellite cell activation and skeletal muscle repair in preclinical models. Approximately 0 articles are indexed (literature last scanned 2026-05-29). US regulatory status: Research use only; not FDA-approved; compounding status unresolved pending PCAC review. Research use only.

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