Important limitations
- Individual claims and source links have not yet completed editorial verification.
- Evidence level, applicable study model, formulation, route and population remain unassigned.
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 mcgWeek 1
Recorded example with no verified study backing; shown for amount literacy only.
- Low-mid range150 mcgWeek 2
Recorded example with no verified study backing; shown for amount literacy only.
- Mid range250 mcgWeek 4
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 MGF
What published studies and recent community write-ups report about amounts, timing and course length. 3 preclinical and 5 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 mouse myocardial infarction model3-month-old male B6/SJL mice after coronary artery ligation | 4.5 mg/kg per day of a stabilized E-peptide (C-terminal amide, D-arginines at positions 14 and 15) | Continuous infusion from a subcutaneous micro-osmotic pump, started at the time of infarction | Subcutaneous osmotic pump | 2 weeks (pump replaced after 7 days)Not applicable | Molecular and Cellular Biochemistry (PubMed)2013 |
| Compared with a scrambled control peptide, the E-peptide preserved contractility on pressure-volume analysis, blunted pathological hypertrophy and reduced apoptotic nuclei in the surviving myocardium two weeks after infarction. The same group had earlier reported benefit from intracoronary E-peptide in sheep, but no dose for that study is given in its abstract, and none of this work involves muscle growth or humans. | |||||
| Preclinical rat heart cell signalingH9C2 rat myocardial cells, plus infarcted rat hearts for expression work | 50 ng/mL of synthetic MGF E peptide | Single exposure, sampled at 5, 15, 30 and 60 minutes | Added to culture medium | Up to 1 hourNot applicable | Molecular Medicine (PubMed Central)2009 |
| The E peptide activated ERK1/2 without activating Akt, the opposite of mature IGF-1, which the authors took as evidence that it signals through a route independent of the IGF-1 receptor. The in vivo part of the study only tracked how IGF-1 and MGF transcripts rose and fell after infarction in rats. | |||||
| Industry replication attempt in muscle cells (negative)C2C12 myoblasts, primary human myoblasts, primary mouse muscle stem cells and cardiac myocytes | Up to 500 ng/mL of native or stabilized MGF peptide | Continuous exposure during proliferation and differentiation assays | Added to culture medium | Days, per assayNot applicable | American Journal of Physiology: Endocrinology and Metabolism2014 |
| Scientists at Novartis and GlaxoSmithKline could not reproduce the claimed increase in myoblast proliferation or the delay in fusion at any concentration tested, while mature IGF-1 and full-length IGF-1Eb worked as expected in the same wells. They also saw no ERK activation in cardiac myocytes from either peptide and concluded that a physiological role for the MGF peptide is in doubt. | |||||
| Community-reported5 rows | |||||
| Community local injection protocol (native MGF) | 100-200 mcg per session, split between both sides of the trained muscle | Every training session, immediately after the workout | Intramuscular into the muscle just trained | 4-6 weeks4-6 weeks off | Community resource2026 |
| A 2026 reference guide treats native MGF as impractical because of its presumed minutes-long half-life and steers readers toward PEG-MGF at 200-400 mcg intramuscularly two or three times a week within 1-2 hours of training. It describes 4-, 5- and 6-week blocks aligned with training phases, all of it community practice rather than trial data. | |||||
| Community post-workout and systemic protocols | 100-200 mcg (native MGF) or 200-500 mcg (PEG-MGF) | Native MGF within 5-10 minutes of the last set; PEG-MGF 2-3 times per week on training days | Intramuscular into the trained muscle (native); subcutaneous abdomen, thigh or deltoid (PEG) | Not specifiedNone described | Community resource2026 |
| This 2026 guide states plainly that no FDA-approved or clinically validated dose exists and that every figure comes from animal work and community reports. It presents the native peptide's local-injection timing as a rationale about mechanotransduction signaling, not as something measured in people. | |||||
| Community dose range with evidence audit | 200-400 mcg per injection (wider span 100-600 mcg) | Shortly after training, on training days only | Local intramuscular injection into the muscle trained | Not specifiedNone described | Community resource2026 |
| This 2026 page records the circulating dose range while stating that no dose-finding study exists in any species and that the widely quoted 5-7 minute half-life cannot be traced to a published measurement, so it withdrew that figure. It also notes that one supporting paper was retracted in 2024 and that the E-peptide is now being studied as a prostate cancer target. | |||||
| Research-vial reconstitution reference | 100-200 mcg per site | Once daily, post-training | Local intramuscular or nearby subcutaneous | Not specifiedNone described | Community resource2026 |
| A 2026 calculator page gives the math for a 2 mg vial in 2 mL of bacteriostatic water (1 mg/mL, so 100 mcg is 10 units) and warns that vendor vials may contain the E-peptide, a fragment or a mislabeled PEG analog. It rates the evidence as low and calls local injection a kinetic bet rather than a proven site-specific effect. | |||||
| Community PEG-MGF cycle | 200-400 mcg per injection (100-200 mcg per side when split bilaterally) | 2-3 times per week, immediately after training | Subcutaneous or intramuscular into the trained muscle | 4-6 weeks (described as 5-6 weeks, 4-8 weeks maximum)At least 4 weeks off before repeating | Community resource2026 |
| This 2026 protocol page for the pegylated form describes two documented dose levels rather than a titration and attributes the longer dosing window to pegylation. It lists blood sugar fluctuations, injection site reactions and theoretical risks of sustained growth factor signaling as reasons for the cycle cap, and acknowledges there are no human trials. | |||||
How a course is commonly described
- Training day: minutes after the sessionCommunity-reported
Community protocols for native MGF inject 100-200 mcg into the muscle just trained within minutes of finishing, split between left and right, on the theory that the peptide is cleared too fast to act anywhere else. No pharmacokinetic study supports or refutes that timing.
- Weeks 1-4Community-reported
Guides run the post-workout injections for every session over roughly a month, or substitute PEG-MGF at 200-400 mcg two or three times a week. Reported effects in this window are described as subjective fullness and recovery, with no measurable endpoint anyone has tracked.
- Weeks 5-6 and breakCommunity-reported
Most frameworks stop at 4-6 weeks (some PEG-MGF pages allow up to 8) and then take 4-6 weeks off, citing a wish to keep satellite cells responsive and to align with training blocks. The break length is convention; nothing has tested whether responsiveness changes at all.
- Preclinical comparisonPreclinical
The only in vivo dosing schedule with a published number is continuous infusion of a stabilized E-peptide at 4.5 mg/kg per day for two weeks in mice after a heart attack, a regimen and purpose with no resemblance to post-workout injections. The one independent attempt to reproduce the muscle-cell effects at up to 500 ng/mL found nothing.
- No human study of injected MGF or PEG-MGF has ever been published, and no study in any species has measured the peptide's half-life. The 5-7 minute figure repeated across the community has no traceable source, so the entire local-injection timing logic rests on an assumption.
- The positive cell and animal results come largely from one academic group, and a 2014 replication attempt by two pharmaceutical companies found no effect on muscle cells at concentrations up to 500 ng/mL. Products sold as MGF may also not be MGF: a doping control laboratory found that a vial of so-called full-length MGF matched none of the expected molecules.
- Mechano growth factors are prohibited at all times under WADA section S2.3. PEG-MGF was listed in the FDA's compounding Category 2 in 2023 because the agency had no human exposure data; its removal in April 2026 followed withdrawal of the nomination, not a safety review.
Sources for this section (13)
- The E-domain region of mechano-growth factor inhibits cellular apoptosis and preserves cardiac function during myocardial infarction
- Mechano-growth factor reduces loss of cardiac function in acute myocardial infarction
- IGF-1 Expression in Infarcted Myocardium and MGF E Peptide Actions in Rat Cardiomyocytes in Vitro
- A strong neuroprotective effect of the autonomous C-terminal peptide of IGF-1 Ec (MGF) in brain ischemia
- 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
- Mass spectrometric characterization of a biotechnologically produced full-length mechano growth factor (MGF) relevant for doping controls
- The 2026 Prohibited List, World Anti-Doping Code
- Certain Bulk Drug Substances for Use in Compounding that May Present Significant Safety Risks
Plus 5 community resources (dosing guides, forum threads and vendor write-ups), reported above but not linked.
Overview
MGF (mechano growth factor) is the name Geoffrey Goldspink's group gave to a splice variant of the IGF-1 gene (IGF-1Ec in humans, IGF-1Eb in rodents) that skeletal muscle switches on for a few days after mechanical loading or injury; the peptide sold under that name is a synthetic 24-residue fragment of the variant's C-terminal E domain. In cell culture and animal models this E-peptide has been reported to activate muscle satellite cells, protect neurons after brain ischemia and limit damage after experimental heart attack, but two pharmaceutical companies failed to reproduce any effect on muscle cells in 2014 and no pharmacokinetic study or human trial of the injected peptide has ever been published. MGF appears on the WADA prohibited list under growth factors (S2.3), the pegylated form PEG-MGF sat in the FDA's compounding Category 2 from 2023 until its nomination was withdrawn in April 2026, and a doping control laboratory found that a product marketed as full-length MGF did not match any known MGF-related molecule.
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 PEG MGF?
Understanding pegylation and extended half-life
- 2
PEG-MGF and Skeletal Muscle
Effects on muscle repair and protection
- 3
PEG-MGF Research in Heart Muscle Repair
Cardiac applications and cell death prevention
- 4
Bone Repair and Growth
Accelerating bone healing through osteoblast proliferation
- 5
Protecting Cartilage
Chondrocyte function and joint health applications
- 6
Dental Applications
Periodontal ligament repair and tooth preservation
What is known and what still needs verification
Available context is organized without assigning unsupported study models or evidence grades.
- Not graded
What is PEG MGF?
Understanding pegylation and extended half-life
- Not graded
PEG-MGF and Skeletal Muscle
Effects on muscle repair and protection
Amounts recorded for 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.
- 1Week 1Sign in for schedule, duration and source context.100 mcg
- 2Week 2Sign in for schedule, duration and source context.150 mcg
- 3Week 4Sign in for schedule, duration and source context.250 mcg
Chemistry identifiers
Sequence, synonyms and registry identifiers as recorded in PubChem, the National Library of Medicine's open chemistry database. Formula, mass and CAS number are summarized at the top of the page.
Sequence
Tyr-Gln-Pro-Pro-Ser-Thr-Asn-Lys-Asn-Thr-Lys-Ser-Gln-Arg-Arg-Lys-Gly-Ser-Thr-Phe-Glu-Glu-Arg-Lys-OH
Also listed as
Mechano growth factor, MGF E-peptide, IGF-1Ec E-domain peptide (human), IGF-IEc C-terminal peptide, MGF 24-mer (YQPPSTNKNTKSQRRKGSTFEERK)
InChIKey
TXMSCWQMYNJNDC-XGJLPCLZSA-N
IUPAC name
(2S)-6-amino-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S,3R)-2-[[(2S)-2-[[2-[[(2S)-6-amino-2-[[(2S)-2-[[(2S)-2-[[(2S)-5-amino-2-[[(2S)-2-[[(2S)-6-amino-2-[[(2S,3R)-2-[[(2S)-4-amino-2-[[(2S)-6-amino-2-[[(2S)-4-amino-2-[[(2S,3R)-2-[[(2S)-2-[[(2S)-1-[(2S)-1-[(2S)-5-amino-2-[[(2S)-2-amino-3-(4-hydroxyphenyl)propanoyl]amino]-5-oxopentanoyl]pyrrolidine-2-carbonyl]pyrrolidine-2-carbonyl]amino]-3-hydroxypropanoyl]amino]-3-hydroxybutanoyl]amino]-4-oxobutanoyl]amino]hexanoyl]amino]-4-oxobutanoyl]amino]-3-hydroxybutanoyl]amino]hexanoyl]amino]-3-hydroxypropanoyl]amino]-5-oxopentanoyl]amino]-5-carbamimidamidopentanoyl]amino]-5-carbamimidamidopentanoyl]amino]hexanoyl]amino]acetyl]amino]-3-hydroxypropanoyl]amino]-3-hydroxybutanoyl]amino]-3-phenylpropanoyl]amino]-4-carboxybutanoyl]amino]-4-carboxybutanoyl]amino]-5-carbamimidamidopentanoyl]amino]hexanoic acid
Limitations and unknowns
Sources
1 link carried over from the earlier page, awaiting verification.