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Muscle & performance

PEG-MGF

The PEGylated, longer-lasting variant of MGF, meant for systemic rather than purely local effect, also without human data.

2 min read 10 sources

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PEG-MGF vial with white powder and the black TPD label on a white podium, next to a large blue 3D molecule model in a bright lab
Preclinical · not approved

Summary

At a glance

Sources checked on 26 Oct 2026

MGF peptide without PEG
24 amino acids

the end piece (E domain) of the IGF-1 variant IGF-1Ec5

Less damaged heart muscle
−35 %

Sheep after a heart attack, MGF peptide without PEG versus comparison group6

Replication without effect
2 companies

two pharmaceutical companies found no effect on muscle precursor cells4

Trials on PEG-MGF
0 trials

no trial with PEG-MGF on ClinicalTrials.gov, as of 26 Oct 202610

  • PEG-MGF is the MGF peptide with attached PEG chains. MGF stands for the end piece of an IGF-1 variant that muscle makes after load or damage.59
  • In rats the MGF variant rose early after a muscle injury, at the same time as markers of activated satellite cells. In cell cultures the peptide promoted the division of muscle precursor cells.12
  • Two pharmaceutical companies could not confirm this: in their experiments the MGF peptide had no effect on muscle cells.4
  • In sheep after a heart attack about 35 percent less heart muscle was damaged with the MGF peptide. In gerbils it protected nerve cells after a disruption of blood flow.68
  • There is no study on PEG-MGF itself. ClinicalTrials.gov lists none (as of October 2026). Everything here is preclinical research, not a recommendation.10
Profile

Updated May 2026

Class
PEGylated IGF-1Ec

MGF

Use
Subcutaneous

in mcg

Half-life
longer than MGF

PEGylated

Status
Preclinical

no human data

Sizes
2 mg

1 size in the shop

Contents 16 sections
  1. At a glance
  2. What is PEG-MGF?
  3. How it works
  4. What you need
  5. Reconstitution
  6. Dosing
  7. Injection
  8. What the research shows
  9. Research status
  10. Side effects
  11. Practice
  12. Storage
  13. Related compounds
  14. FAQ
  15. Glossary
  16. Sources

What is PEG-MGF?

PEG-MGF is MGF with attached PEG chains (PEGylation). These protect the molecule from fast breakdown, so PEG-MGF lasts markedly longer than the very short-lived normal MGF. The idea: a systemic rather than only local effect, with less frequent injections.

As with normal MGF: the human data is thin, most comes from mechanistic understanding.

Comparison

Relatives from the IGF-1 family

How PEG-MGF differs from the other IGF-1 derivatives in the lexicon. Tap a card to open its entry.

MGF peptide with PEG chains PEG-MGF
MGF peptide without PEG MGF (Mechano Growth Factor) Modified IGF-1 IGF-1 LR3 IGF-1R

According to studies MGF and PEG-MGF do not act via the IGF-1 receptor. No own receptor is known. 28

How it works

PEG-MGF acts like MGF via activating satellite cells in muscle, just longer, because PEGylation slows breakdown. This allows less frequent dosing (for example twice a week) instead of the time-critical post-workout shot of normal MGF.

Where it acts

Where the MGF peptide acted in experiments

Tap a point or a card. All from cell and animal studies with MGF without PEG.

  1. Skeletal muscle

    Rats: MGF variant rises early after injury. Cell culture: findings conflicting1

    Observed in trials
  2. Heart

    Sheep and mice after infarction: less damage, pump function better preserved (without PEG)6

    Observed in trials
  3. Brain

    Gerbils: nerve cells protected after a disruption of blood flow (without PEG)8

    Observed in trials

Known targets2

Compound MGF-E-Peptid, 24 Aminosäuren (keine Datenbank-Kennung für PEG-MGF): one described target, According to studies not needed for the effect of the MGF peptide, no own receptor is known.

IGF-1 receptor
Gene
IGF1R
UniProt
P08069
ChEMBL
CHEMBL1957
Action
According to studies not needed for the effect of the MGF peptide, no own receptor is known
Translucent crossed glass muscle fibres with many small glowing bubbles on their surface, blue 3D molecules floating around them
Symbolic image.

What you need

Supplies

2 things, numbered as in the picture

Tick off what you already have. Vial and BAC water are our real shop photos at the same size.

PEG-MGF vial and bacteriostatic water at the same size with the black TPD label, next to two U-100 insulin syringes, two alcohol swabs and a sharps container with a blue lid

  1. PEG-MGF vial

    The PEG-MGF vial (lyophilized powder).

    In the shop

  2. Water and supplies

    Bacteriostatic water, U-100 insulin syringes, alcohol swabs.

    In the shop

Reconstitution

Use the peptide calculator. A 2mg vial with 1ml water gives 2000mcg per ml, 200mcg is then 10 units on the U-100 syringe. Just add the water to the vial and let it dissolve.

Step by step

Dissolving the powder

Four steps, the same for every vial size.

  1. 1Wipe the cap

    Clean the rubber stopper with an alcohol swab.

  2. 2Add BAC water

    Just add it, it does not matter if it hits the powder directly.

  3. 3Swirl or shake

    Until everything has dissolved, both are fine.

  4. 4Draw up

    With the U-100 insulin syringe.

Less water higher concentration fewer units on the syringe Example: 2 mg + 1 ml = 2 mg/ml

Dosing

Dosing

Dosing, titration and syringe

Loading the dosing information …

  • Getting started and stepping up, drawn as a staircase
  • Units on the U-100 syringe for every step
  • How long one vial lasts

Injection

The injection is subcutaneous, into the fat layer under the skin. Common spots are the abdomen (keep about two finger-widths clear of the navel), the front and the inner side of the thigh, or the back of the upper arm.

The short version:

Injection

Where and at what angle

Pick a spot or switch the angle. Subcutaneous means: into the fat layer, not the muscle.

Rotate the spot each time, never the same one twice in a row.

90°More fat under the skin

Rule of thumb: where there is more fat under the skin, insert straight at 90 degrees. In lean people with little fat, 45 degrees, so the needle stays in the fat layer. Simplified diagram.

  1. Clean the spot with an alcohol swab and let it dry

  2. Pinch up a small fold of skin

  3. Insert the needle: at 90 degrees where there is more fat under the skin, at 45 degrees in lean people with little fat

  4. Inject slowly, wait a moment, then withdraw

  5. Put the needle straight into the sharps container

Rotate the site each time so the tissue does not get irritated. Never the same spot twice in a row.

What the research shows

The basis is the same as for MGF (Hill & Goldspink, 2003): MGF activates satellite cells after tissue damage. PEGylation is a pharmacological modification to extend duration. There are no standalone human studies on PEG-MGF, it is experimental.

Study results

What the trials measured

Interactive: switch tabs, tap points, show or hide arms. Arms are named relative to each other, no dosing advice.

Damaged heart muscle after infarction6

Change compared with the comparison group, in percent

Heart muscle at risk6 Sheep, 8 days after the infarction
Without MGF peptide (comparison) 0%
MGF peptide without PEG -35%

Value according to the abstract. The MGF peptide without PEG was tested in sheep. There is no such measurement for PEG-MGF. None of this has been studied in humans.

Glass block with embedded muscle tissue in cross-section, a few muscle fibres in the middle glowing brighter than the rest
Symbolic image.

Research status

Where the research stands

There is no study of PEG-MGF itself. The MGF peptide without PEG has been studied in cell cultures, rats, mice, gerbils and sheep. As of 26 Oct 2026. 10

  1. Preclinical Cell cultures and animal models, only without PEG
  2. Phase 1 no registered trial
  3. Phase 2 no registered trial
  4. Phase 3 no registered trial
  5. Approval not yet
Not approved and no registered human trial. PEG-MGF is a modification for which no study has been published.10

So far there is no registered trial in humans. 10

Side effects

  • Solid human data are missing.
  • Local reactions at the injection site.
  • As with IGF-related compounds, a growth-promoting signal is theoretically critical with pre-existing growths.

Practice

  1. Keep expectations low, the effect in humans is not established.

  2. The only advantage over MGF is the longer duration (less frequent dosing).

  3. Banned in official competition.

Two light blue dumbbells, two white cubes and a shaker with a protein shake on a white bench in a bright room

Storage

Before mixing the powder is robust, normal room temperature (around 20 to 25 degrees) is fine, ideally kept in the dark. After mixing, keep in the fridge (2 to 8 degrees), do not freeze. It stays good there for at least 4 to 6 months with barely any loss of potency, in practice considerably longer. Swirl or shake to mix, both are fine.

Shelf life

How long it keeps

Undissolved (powder) Room temperature, around 20 to 25 degrees, dark

Robust, no fridge needed.

Dissolved (mixed) Fridge, 2 to 8 degrees, do not freeze

At least 4 to 6 months with barely any loss of potency.

  • Keep it dark
  • Dissolved: 2 to 8 degrees
  • Note the mixing date on the vial
Nine vials with white powder and blue caps in the door shelf of a bright fridge
Powder dark at room temperature, once dissolved into the fridge (2 to 8 degrees), stable there for at least 4 to 6 months. Symbolic image.

Related

Related compounds

Same targets, blends with PEG-MGF or a different path: all in the TPD lexicon.

PEG-MGF
MGF (Mechano Growth Factor) The same peptide without PEG chains IGF-1 LR3 Modified IGF-1, acts via the IGF-1 receptor HGH 191AA (Somatropin) Growth hormone, stimulates IGF-1 production Ipamorelin Different route via growth hormone release BPC-157 Different peptide focused on repair

FAQ

Common questions about PEG-MGF

Short answers, each backed by the sources below.

Is PEG-MGF approved or studied in humans?

No. There is no approval and no published study on PEG-MGF, not even in animals. As of 26 October 2026 ClinicalTrials.gov lists no trial with it. All data here concern the MGF peptide without PEG.109

What exactly is MGF?

The IGF-1 gene is read in different ways as needed. One variant, IGF-1Ec in humans, rises in muscle after load or damage and was named mechano growth factor. The MGF peptide used is usually the synthetic end piece of 24 amino acids. According to a review from 2010 such a peptide has never been found in the body.51

What did the muscle studies show?

In rats the MGF variant rose early after a muscle injury and fell again after a few days, at the same time as markers of activated satellite cells. In cell cultures the end piece promoted the division of muscle precursor cells and slowed their maturation, independently of the IGF-1 receptor. In human muscle cells it acted in cells from young donors, not in those from older ones.123

Are there doubts about these results?

Yes. In 2014 two pharmaceutical companies tried to reproduce the findings. The MGF peptide neither increased the division of muscle cells nor slowed their maturation, not even in muscle stem cells from mice. A stabilised form did not work either. The authors question whether MGF has any role in the body at all.4

What is known about heart and brain?

In sheep after a heart attack about 35 percent less heart muscle was damaged with the MGF peptide. In mice pump function was better preserved after an infarction, tested with a stabilised form without PEG. In gerbils the peptide protected nerve cells after a brief disruption of blood flow in the brain.678

What is PEGylation supposed to achieve?

PEG chains are meant to protect a peptide from rapid breakdown and keep it in the body longer. Whether this works for MGF and what then happens in the body has not been tested by any published study. A review from 2026 lists PEG-MGF among the peptides with no human studies.9

Which side effects are known?

There are no solid data. A review of peptides around growth hormone and IGF-1 lists hormonal and metabolic disturbances, fluid retention, muscle and joint pain and injection site reactions as reported problems. A growth-promoting signal is considered a plausible but unproven risk there.9

Glossary

Terms explained briefly

Dotted words in the text open these explanations directly.

E domain
The end piece of the IGF-1 precursor, which differs between variants. For MGF it is the peptide that is studied.
IGF-1
Insulin-like growth factor 1. It is made mainly in the liver under growth hormone, but also in muscle itself.
Lyophilisate
Freeze-dried powder. Without water a peptide keeps much longer.
Mechano growth factor (MGF)
Name of an IGF-1 variant that forms in muscle after load. As a peptide usually the synthetic end piece of 24 amino acids.
PEGylation
Attaching polyethylene glycol chains to a compound. This is meant to slow breakdown and extend the duration of action.
Preclinical
Research before first use in humans, in cell cultures and animal models. Results cannot be transferred directly to humans.
Satellite cells
Resting stem cells at the edge of muscle fibres. After an injury they divide and help with repair.
Splice variant
A form of a gene in which the cell joins different sections. This way one gene yields several proteins.
Subcutaneous
Into the fat layer just under the skin.

Evidence

Sources

Show all 10 sourcesHide sources 9 Studies1 Trial registry checked 26 Oct 2026

Studies

  1. MGF variant and satellite cells after muscle damage (rats)

    Hill und Goldspink, The Journal of Physiology, 2003

    DOI 10.1113/jphysiol.2002.035832 PMID 12692175
    Checked 26 Oct 2026 via doi.org, Crossref, PubMed, PMC (Volltext)
  2. MGF end piece and division of muscle precursor cells (cell culture)

    Yang und Goldspink, FEBS Letters, 2002

    DOI 10.1016/s0014-5793(02)02918-6 PMID 12095637
    Checked 26 Oct 2026 via doi.org, Crossref, PubMed
  3. MGF-E peptide in human muscle cells of different ages

    Kandalla et al., Mechanisms of Ageing and Development, 2011

    DOI 10.1016/j.mad.2011.02.007 PMID 21354439
    Checked 26 Oct 2026 via doi.org, Crossref, PubMed
  4. Replication: MGF peptide without effect on muscle cells

    Fornaro et al., American Journal of Physiology Endocrinology and Metabolism, 2014

    DOI 10.1152/ajpendo.00408.2013 PMID 24253050
    Checked 26 Oct 2026 via doi.org, Crossref, PubMed
  5. Review: what MGF is and what remains open

    Matheny et al., Endocrinology, 2010

    DOI 10.1210/en.2009-1217 PMID 20130113
    Checked 26 Oct 2026 via doi.org, Crossref, PubMed, PMC (Volltext)
  6. MGF peptide after heart attack (sheep)

    Carpenter et al., Heart, Lung and Circulation, 2008

    DOI 10.1016/j.hlc.2007.04.013 PMID 17581790
    Checked 26 Oct 2026 via doi.org, Crossref, PubMed
  7. Stabilised MGF-E peptide after heart attack (mice)

    Mavrommatis et al., Molecular and Cellular Biochemistry, 2013

    DOI 10.1007/s11010-013-1689-4 PMID 23712705
    Checked 26 Oct 2026 via doi.org, Crossref, PubMed, PMC (Volltext)
  8. MGF end piece protects nerve cells after disrupted blood flow (gerbils)

    Dluzniewska et al., The FASEB Journal, 2005

    DOI 10.1096/fj.05-3786fje PMID 16144956
    Checked 26 Oct 2026 via doi.org, Crossref, PubMed
  9. Review of growth hormone axis peptides and their self-administration

    Dominikowski et al., Frontiers in Endocrinology, 2026

    DOI 10.3389/fendo.2026.1822475 PMID 42395176
    Checked 26 Oct 2026 via doi.org, Crossref, PubMed, PMC (Volltext)

Trial registry

  1. Search on ClinicalTrials.gov (no trial with PEG-MGF)

    ClinicalTrials.gov, U.S. National Library of Medicine

    Checked 26 Oct 2026 via ClinicalTrials.gov API v2

In the shop

PEG-MGF in the catalog

Sizes, prices and shipping times are on the product page.

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