PEG-MGF Research: A Conjugate With No Published Characterisation
This page is short on purpose. PEG-MGF has no origin paper, no published structure, no measured mass, no pharmacokinetic data and no study of its own in cells, animals or people. A long article about polyethylene glycol chemistry would disguise that rather than report it.
What is PEG-MGF?
What is PEG-MGF? The name describes a construction: the mechano growth factor peptide — the 24-residue C-terminal fragment of the human IGF-1Ec E domain — with one or more chains of polyethylene glycol attached. The peptide half is covered on the MGF page, including why its identity is contested. The PEG half is ordinary bioconjugate chemistry.
The name conveys no specification. A pegylated peptide is defined by its PEG molecular weight, chain count and attachment site (Mero et al. 2011, PMID 21674328) — none of which the label fixes, so two products sold as “PEG-MGF” can be different molecules, with no published reference standard to compare either against.
Reference data
The gaps are the content. Estimating them would be inventing them.
| Property | Value |
|---|---|
| Peptide component | The 24-residue MGF peptide, YQPPSTNKNTKSQRRKGSTFEERK |
| Peptide provenance | C-terminal 24 residues of UniProt IGF1_HUMAN isoform P05019-4 |
| PEG size, chain count, attachment site | Not published |
| Molecular weight | Not determinable — a PEGylated product is a distribution of species, not one mass |
| CAS number | None identified |
| Storage | Lyophilized powder stored cold and dry, protected from light |
What PEGylation does — as a technique
Context, not the subject of this page. PEGylation modifies pharmacokinetics and stability, not potency. Veronese & Pasut (2005, Drug Discov Today, PMID 16243265) give the standard account: PEG increases hydrodynamic radius, slowing renal filtration — the dominant effect for small peptides — while shielding the backbone from proteases. The same literature records the trade-off: shielding can block the surface a molecule needs to engage its target, so whether a conjugate stays active is answered per molecule. Here it cannot be answered at all, because the target through which the MGF peptide is supposed to act has never been identified.
Evidence status
There are no research models, because there is no published research on this conjugate: everything above is either PEGylation chemistry or MGF peptide biology, neither specific to the pegylated molecule.
What is not established. No peer-reviewed characterisation of PEG-MGF exists: no structure, no PEG size or attachment site, no measured mass, no validated purity method. No pharmacokinetic study exists for the pegylated or the unmodified peptide — which matters, because prolonged half-life is the usual rationale offered for pegylating it, and there is no baseline figure it could improve on. No cell, animal or human study of the conjugate has been reported; no approved product contains it; it holds no registered indication anywhere. Dominikowski et al. (2026, Front Endocrinol, PMID 42395176) list it among IGF-1 analogues in unregulated use, in a review stratified from randomised trial data down to a complete absence of human studies — this one sits at the bottom. The parent peptide adds its own doubt: Fornaro et al. (2014, PMID 24253050) reported no apparent effect of the MGF peptide on myoblasts or primary muscle stem cells.
The literature for this specific conjugate does not exist, so this page is short by design. A longer one would be padding, and padding here would misrepresent how much is known.
How to verify this compound yourself
PEGylation complicates every standard identity check, and understanding how is the practical value of this page. Background: published analysis of unregulated unmodified MGF found C-terminally amidated analogues rather than the labelled molecule (Esposito et al. 2012, PMID 22328223) — covered on the MGF page. No published analysis has examined a pegylated product.
- Mass spectrometry gives a distribution, not a peak — PEG reagents are polydisperse, so a correctly pegylated product produces a ladder of species separated by the PEG repeat unit. A certificate reporting one clean peptide mass is describing either the unmodified peptide or something that was not measured.
- HPLC purity needs a matching method — a conjugate chromatographs differently from the free peptide, and the degree of conjugation appears as separate species. A purity figure is interpretable only if the method was built for the conjugate.
- Ask what the certificate describes, not only how pure it is — identity confirmation carries the weight here.
See how to read a COA, how to verify peptide purity, and the verify tool for the batch on a vial in hand.
Where PEG-MGF sits
MGF is the unmodified parent peptide, with no identified receptor. IGF-1 LR3 and IGF-1 DES are engineered IGF-1 analogues defined by reduced binding-protein affinity — both far better characterised than this. Working the opposite way: GDF-8 is myostatin, a negative regulator rather than an agonist; follistatin-344 antagonises it; ACE-031 is a receptor decoy whose programme was halted on safety grounds. Family context only.
Research-grade sourcing and verification
For laboratory research use only. PEG-MGF is not held in stock; it is listed as available to order in the sourcing catalogue, with a typical lead time of two to three weeks and a quote on request. Material ships with a per-batch Certificate of Analysis reporting HPLC purity (%) and mass-spec identity confirmation. On a compound with no published reference characterisation, documenting what a specific batch contains is the only thing that can honestly be offered.
Verify a batch
Every order ships with a per-batch Certificate of Analysis. Have a vial in hand? Enter its lot number to look up the COA for that exact batch.
Frequently asked questions
What is PEG-MGF?
Has PEG-MGF been studied?
Literature cited
- Dominikowski A, Rekos Z, Olejarz M, Szczepanek-Parulska E, Domin R, Ruchala M. “The emerging landscape of performance-enhancing peptides modulating GH-IGF1 axis.” Front Endocrinol (Lausanne). 2026;17:1822475. PMID 42395176. pubmed.ncbi.nlm.nih.gov/42395176.
- Veronese FM, Pasut G. “PEGylation, successful approach to drug delivery.” Drug Discov Today. 2005;10(21):1451–8. PMID 16243265. pubmed.ncbi.nlm.nih.gov/16243265.
- Mero A, Clementi C, Veronese FM, Pasut G. “Covalent conjugation of poly(ethylene glycol) to proteins and peptides.” Methods Mol Biol. 2011;751:95–129. PMID 21674328. pubmed.ncbi.nlm.nih.gov/21674328.
- Esposito S, Deventer K, Van Eenoo P. “Characterization and identification of a C-terminal amidated mechano growth factor (MGF) analogue in black market products.” Rapid Commun Mass Spectrom. 2012;26(6):686–92. PMID 22328223. pubmed.ncbi.nlm.nih.gov/22328223.
- Fornaro M, Hinken AC, Needle S, et al. “Mechano-growth factor peptide, the COOH terminus of unprocessed insulin-like growth factor 1, has no apparent effect on myoblasts or primary muscle stem cells.” Am J Physiol Endocrinol Metab. 2014;306(2):E150–6. PMID 24253050. pubmed.ncbi.nlm.nih.gov/24253050.
- UniProt Consortium. “IGF1_HUMAN (P05019).” uniprot.org/uniprotkb/P05019.
RESEARCH USE ONLY — NOT FOR HUMAN CONSUMPTION. All products are sold strictly for in-vitro laboratory research and are not intended for human or veterinary use, ingestion, or administration. Nothing on this page is a medical or efficacy claim. You must be 21 or older to browse this catalog.