Molecular profile
- Sequence
- PEG-Suc-Tyr-Gln-Pro-Pro-Ser-Thr-Asn-Lys-Asn-Thr-Lys-Ser-Gln-Arg-Arg-Lys-Gly-Ser-Thr-Phe-Glu-Glu-Arg-Lys-Cys
- Molecular Formula
- C 121 H 200 N 42 O 39
- Synonyms
- Pegylated MGF, PEG IGF-1 Ec, PEG myotrophin
PEG-MGF
PEGylated Mechano-Growth Factor is a modified form of MGF, itself a modified form of IGF-1.
Dosing & scaling, explained
The moderated mass amounts below are retained for comparison. Near-duplicates, mix-dependent volumes and device markings are excluded. This is educational source context, not a protocol or recommendation.
Mass amounts available for comparison
- Lower range100 mcgDose
Recorded example with no verified study backing; shown for amount literacy only.
- Mid range500 mcgDose
Recorded example with no verified study backing; shown for amount literacy only.
Only mcg or mg amounts are retained. The calculator derives mL, syringe units or pen clicks from the current vial strength, water volume and device.
No independently verified schedule
Evidence context
No clinical amount or schedule is inferred from this material. Source verification is pending, and every displayed amount remains educational context rather than guidance.
Storage, handling and interpretation
Product identity
Verify the exact compound, formulation and amount against the product label or certificate before calculation.
Storage & handling
Follow the product label, certificate and validated laboratory SOP; no universal storage assumption is applied here.
Prepared solutions
Label concentration and preparation date, use sterile technique where applicable, and follow a validated stability protocol.
Reported protocols for PEG-MGF
What published studies and recent community write-ups report about amounts, timing and course length. 3 preclinical and 4 community-reported rows, each linked to its source. These are descriptions of what others report, not instructions, and nothing here is medical advice.
| Context | Dose | Frequency | Route | Course | Source |
|---|---|---|---|---|---|
| Preclinical3 rows | |||||
| Preclinical: MGF injected into contused mouse muscleMice with a gastrocnemius contusion and macrophage depletion | 5 mcg of MGF peptide in 20 microlitres | Three doses: immediately after the injury and again at 1 and 2 days | Injection into the injured muscle; controls received buffer | 3 days of dosing, with analysis at 14 days after injuryNot applicable | Frontiers in Physiology (PubMed Central)2019 |
| The injections did not improve the diameter, number or area of regenerating muscle fibres, but they did reduce the fibrotic area at 14 days along with inflammatory cytokines, chemokines, an oxidative-stress marker and several matrix metalloproteinases. The peptide used was unmodified MGF, not the pegylated form, and the model combined injury with macrophage depletion, which the authors note limits how far the result generalises. | |||||
| Preclinical: MGF E domain after myocardial infarction in sheepSheep with infarcts induced by microsphere injection | 200 nM of the MGF E-domain peptide (mature IGF-1 and full-length MGF also tested at 200 nM in the first experiment) | Administered to the heart after the infarct | Intramyocardial, into the area around the infarct | Animals assessed by echocardiography and killed 8 days after the infarctNot applicable | Heart, Lung and Circulation (PubMed)2008 |
| Hearts given the E-domain peptide kept more function and had about 35% less compromised myocardium than controls, with cleaved caspase 3 staining absent in treated hearts, which the authors read as reduced infarct expansion. Only the E domain helped; mature IGF-1 and full-length MGF did not, and the abstract gives no animal numbers. | |||||
| Preclinical: failed replication in muscle cellsC2C12 myoblasts, primary human skeletal muscle myoblasts, primary mouse muscle stem cells and cardiac myocytes | Concentrations up to 500 ng/mL | Single exposure in culture | In vitro | Not applicableNot applicable | American Journal of Physiology: Endocrinology and Metabolism (PubMed)2014 |
| Two pharmaceutical laboratories could not reproduce the claimed effects of the MGF peptide: it did not increase proliferation of any cell type, did not delay myoblast fusion into myotubes and did not activate ERK signalling in cardiac myocytes, while mature IGF-1 and full-length IGF-1Eb produced clear responses. The authors conclude that the physiological role of the MGF peptide is in question, which is the main counterweight to the positive animal reports. | |||||
| Community-reported4 rows | |||||
| Post-workout community protocol | 200 mcg (lower end) or 200-400 mcg | 2-3 times per week, within about 30 minutes of finishing the session | Subcutaneous or intramuscular into the muscle group trained; bilateral muscles can be split between sides | 5-6 weeks (4-8 weeks described as the maximum)At least 4 weeks off before repeating | Community resource2026 |
| This August 2026 protocol page states plainly that PEG-MGF has no human trials and that all dosing is extrapolated from animal work and self-reports. It gives the pegylated half-life as 48-72 hours against 5-7 minutes for unmodified MGF as the reason for twice-weekly rather than daily dosing, a figure that has never been measured in a person. | |||||
| Training-day intramuscular protocol | 300-400 mcg | 2-3 times per week on training days, within 1-2 hours after the session | Intramuscular into the trained muscle | 4-6 weeks4-6 weeks off | Community resource2026 |
| This guide treats 200-400 mcg as the standard band, calling doses under 200 mcg probably too small and doses over 400 mcg no better in community reports. It frames cycling as a way to keep the response to an exogenous satellite-cell signal and to line up with training blocks rather than as a receptor-desensitisation problem, and it offers an IGF-1 LR3 pairing with no supporting data. | |||||
| Tiered dosing with bilateral site splits | 100-200 mcg (low), 200-400 mcg (mid) or 400-500 mcg (high); 150-200 mcg for a single lagging muscle | 2-3 times per week, immediately after training that muscle | Intramuscular, split between both sides for paired muscles (for example 100 mcg per deltoid) | 4 weeks for a first block, 4-6 weeks otherwiseAt least 4 weeks off | Community resource2026 |
| This page insists the injection must follow the training session rather than precede it, on the argument that the point is to pair the signal with the window of mechanical damage, and it describes the compound as an adjunct rather than a standalone muscle builder. Every figure is presented as documented community practice, with no human study behind the tiers. | |||||
| Quality and dose critique | No dose supported; one vendor sample labelled 5 mg assayed at 6.35 mg, a 27% overage | Not applicable | Not applicable | Not applicableNot applicable | Community resource2026 |
| This February 2026 analysis quotes the FDA's finding of no human exposure data by any route and argues that every circulating dose, interval and timing rule was invented. It also explains why a pegylated peptide cannot be verified with the usual tests, since mass spectrometry returns a distribution rather than a single peak, and notes that the marketed 24-residue sequence ending STFEEHK differs by 19 daltons from the UniProt sequence ending STFEERK. | |||||
How a course is commonly described
- Training day 1Community-reported
Community protocols inject 100-200 mcg into the muscle group just trained, within about 30 minutes of finishing, on the argument that the dose should land inside the window of mechanical damage. Paired muscles are often split, for example 100 mcg per side.
- 48-72 hours laterCommunity-reported
A second weekly injection of the same size follows 48-72 hours after the first, with a subcutaneous dose substituted if there was no training that day. The pegylated half-life of 48-72 hours is given as the reason daily dosing is not used, although that figure has never been measured in a human.
- Weeks 1-6Community-reported
The course runs 4-6 weeks at 200-400 mcg two or three times a week, lined up with a training block. Guides suggest holding the lower end for a first block and describe the compound as something used alongside other agents rather than on its own.
- BreakCommunity-reported
At least 4 weeks off is the common rule, sometimes 4-6 weeks, with the stated aim of keeping the IGF-1 pathway responsive and limiting sustained growth-factor signalling. No study has examined either the course length or the break.
- Preclinical comparisonPreclinical
Published experiments gave unmodified MGF directly into tissue: 5 mcg into an injured mouse muscle on three consecutive days, or 200 nM of the E domain into sheep heart after an infarct. Nothing published describes a multi-week course of the pegylated form in any species.
- The FDA's compounding page states that it has not identified any human exposure data for PEG-MGF by any route and that it lacks the information needed to know whether the substance would cause harm in people. The pegylated form was nominated for the 503A bulk substances list and the nomination was later withdrawn, which is a procedural event rather than a safety clearance.
- PEG-MGF has no PubChem compound record and no defined molecular weight, because pegylation produces a distribution of chain lengths. The 24-residue sequence sold as MGF also circulates in two versions that differ by one residue and 19 daltons, so a vial labelled MGF is ambiguous without sequencing.
- The 48-72 hour half-life that justifies twice-weekly dosing has never been measured in a person, the positive muscle-cell findings failed to replicate in two pharmaceutical laboratories at up to 500 ng/mL, and WADA prohibits mechano growth factors at all times under section S2.3.
Sources for this section (8)
- Impaired Skeletal Muscle Regeneration Induced by Macrophage Depletion Could Be Partly Ameliorated by MGF Injection
- Mechano-growth factor reduces loss of cardiac function in acute myocardial infarction
- 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
- Mechano Growth Factor E peptide (MGF-E), derived from an isoform of IGF-1, activates human muscle progenitor cells and induces an increase in their fusion potential at different ages
Plus 4 community resources (dosing guides, forum threads and vendor write-ups), reported above but not linked.
Overview
PEG-MGF is a polyethylene glycol conjugate of mechano growth factor, the 24-residue C-terminal piece of the E domain of IGF-1Ec, a splice variant of IGF-1 that muscle produces after mechanical loading and damage. PubChem holds no compound record for either MGF or its pegylated form: a search returns only two vendor-submitted substance entries with no linked compound and no computed formula or mass, which is why no chemistry card is shown here. That is a property of the chemistry rather than a gap in curation, because polyethylene glycol is a polymer with a chain-length distribution, so a pegylated peptide is a family of species separated by 44-dalton steps instead of one molecule with a single mass, and vendor listings that quote one molecular weight are quoting a figure that does not exist as a specification. The underlying biology is real and the unmodified MGF peptide has been injected into animal muscle and heart in published experiments, but the FDA states it has found no human exposure data for PEG-MGF by any route, no trial of it is registered, and WADA prohibits mechano growth factors at all times.
What researchers are exploring
These themes organize the educational information currently available. Individual claims remain under source review and are not treatment claims.
- 1
What is Pegylation?
Understanding the pegylation process
- 2
Research on PEG-MGF
Scientific findings and applications
What is known and what still needs verification
Available context is organized without assigning unsupported study models or evidence grades.
- Not graded
What is Pegylation?
Understanding the pegylation process
- Not graded
Research on PEG-MGF
Scientific findings and applications
Amounts recorded for PEG-MGF
These amount records are independent from vial strength, reconstitution volume and measuring device. A recorded source is not the same as study backing, and these values are not recommendations.
- 1Dose · lower endpointSign in for schedule, duration and source context.100 mcg
- 2Dose · upper endpointSign in for schedule, duration and source context.500 mcg
Identity, limitations and unknowns
Important limitations
- Individual claims and source links have not yet completed editorial verification.
- Evidence level, applicable study model, formulation, route and population remain unassigned.
Sources
1 link carried over from the earlier page, awaiting verification.