PEG-MGF 2 mg vial dosage

What PEG-MGF is

Class:

Synthetic PEGylated analogue of a splice variant of IGF-1 (mechano growth factor)

Also called:

Pegylated Mechano Growth Factor, PEGylated MGF, IGF-1Ec peptide analogue

Used for:

Marketed to consumers for muscle repair and growth after resistance training. Never approved for human use; FDA states it has identified no human exposure data on it by any route.

Human evidence:

Animal / lab only. Human evidence is essentially absent. FDA states it has identified no human exposure data on PEG-MGF administered by any route. The literature on native mechano growth factor is rodent and cell-culture work - for example, MGF messenger RNA rising quickly after muscle damage in rats (Hill 2003), and a synthetic MGF E peptide improving transplanted muscle-cell engraftment in mice (Mills 2007) - not a study of the synthetic, PEGylated consumer product. The one human study usually cited (Hameed 2003) measured MGF messenger RNA switched on by exercise in people's own muscle; nobody was injected. Researchers at two pharmaceutical companies could not reproduce the claimed effects of the MGF peptide on muscle cells (Fornaro 2014). No completed human trial has tested injected PEG-MGF for any outcome.

US status:

Research use only. Not an FDA-approved drug. FDA's bulk drug substances safety-risk page (current as of 04/22/2026) lists PEG-MGF in the "nominated but withdrawn" table - a substance previously flagged in Category 2 whose nomination was withdrawn by the nominator, not a substance found safe or added to the 503A Bulks List. It is not eligible for lawful 503A compounding and is sold to consumers as an unverified research chemical. Prohibited at all times in sport under the WADA 2026 Prohibited List, section S2.3, Growth Factors and Growth Factor Modulators, which names "Mechano growth factors (MGFs)" explicitly.

The full picture, with every study: PEG-MGF guide.

How to mix a 2 mg PEG-MGF vial

For this vial: 1 mL of bacteriostatic water makes 2 mg/mL, so 300 mcg is 15 units (0.15 mL) on a U-100 insulin syringe. Pick a different volume from the units table if you want bigger or smaller draws; the number of doses stays the same.

1. Wipe the rubber stoppers of both the peptide vial and the bacteriostatic water vial with an alcohol swab and let the alcohol dry. ^[3][4]
2. With a new sterile needle and syringe, draw up the amount of bacteriostatic water you have chosen for the dilution. ^[3][4][5]
3. Inject the water into the peptide vial by aiming the stream against the inside glass wall, which helps prevent foaming. ^[6]
4. Swirl or roll the vial gently until the powder has fully dissolved; do not shake it. Do not inject the solution if it is cloudy or has particles in it. ^[3][4][6]
5. Label the vial with the date and time it was mixed, the amount of water added and how long it can be used after mixing. ^[3]
6. Store the mixed vial in the refrigerator at 2-8°C (36-46°F) and do not freeze it. ^[6]

Step by step with pictures: how to reconstitute peptides. About the water itself: bacteriostatic water.

Storing PEG-MGF vials

• Freeze-dried (lyophilized) peptide keeps far longer than peptide in solution; peptide suppliers advise storing the powder at -20°C away from bright light. ^[7]
• Protect peptide vials from heat and light. ^[7][8]
• Avoid repeated freeze-thaw cycles; a prescription peptide label also says not to freeze a vial once it has been mixed. ^[6][7]
• Once a multi-dose vial, such as bacteriostatic water, has been opened (needle-punctured), date it and discard it within 28 days unless its manufacturer states another date. ^[9][10]

More detail: peptide storage and shelf life.

Injecting safely

• Clean the injection site with an alcohol swab and let the skin dry completely before injecting. ^[11][12]
• Pinch up a fold of skin and fat (not muscle) and insert the needle at a 45- to 90-degree angle: 90 degrees where there is enough fatty tissue, 45 degrees where there is little. ^[11][12][13]
• Pulling back on the plunger (aspiration) is not necessary for a subcutaneous injection, because the chance of the needle being in a blood vessel is small. ^[11]
• Inject slowly, at roughly 10 seconds per mL. ^[11]
• Common sites are the belly, the thigh and the upper arm; rotate sites, keeping each injection at least 1 inch (2.5 cm) from the last. ^[6][11][12]

Hygiene and warning signs

• Use a new sterile needle and syringe for every injection and every time you enter a vial; never reuse them. ^[5][9][12]
• Never share needles, syringes or pens with anyone, even if the needle is changed; unsafe injection practices spread hepatitis B, hepatitis C and HIV. ^[5][8][9]
• Put used needles and syringes in a sharps disposal container straight away (FDA-cleared if possible), never loose in the trash, recycling or toilet, and dispose of the container following your community's guidelines. ^[14][15]
• Contact a health care provider if the injection site shows signs of infection, such as redness, swelling, red streaks or a fever. ^[12]

Where to inject: subcutaneous injection sites.

How PEG-MGF works

• Mechano growth factor is the name given to a form of IGF-1 made when the IGF-1 gene is spliced differently in muscle, especially after mechanical stress; in humans the variant is known as IGF-1Ec. The peptide sold and studied as MGF is a 24-amino-acid piece from the C-terminal end of its E domain, which laboratories synthesise separately from mature IGF-1. ^[16][17]
• In cell culture the E-domain peptide behaved differently from mature IGF-1, increasing myoblast proliferation while holding back terminal differentiation, and blocking the IGF-1 receptor with an antibody did not stop that effect, which the authors read as action through some other receptor. ^[18]
• PEG-MGF is a PEGylated version of that peptide sold as a research chemical. A 2026 review of growth-hormone-axis peptides found no peer-reviewed human study of it - not even one reporting a route of administration - and points out that PEGylation changes how a peptide is distributed and cleared, so results from the natural splice variant or the plain E-domain peptide cannot be assumed to carry over. ^[17]

What the PEG-MGF research found

Human evidence: animal / lab only. Each result says what was studied.

• Human studyIn the human study most often cited behind the marketing, 8 young men aged 25-36 and 7 older men aged 70-82 did ten sets of six single-leg knee extensions at 80% of their one-repetition maximum. MGF messenger RNA in the muscle rose significantly in the young group but not in the older group. The study measured the gene the participants' own muscle switched on; nobody was injected with anything. ^[19]
• Animal studyIn rats, MGF messenger RNA in the tibialis anterior rose quickly after muscle damage from stretch-plus-stimulation or from a bupivacaine injection and then declined within a few days, while the systemic IGF-IEa variant rose more slowly as MGF declined. ^[20]
• Lab studyTwo pharmaceutical companies tried and failed to reproduce the effects claimed for the MGF peptide. Concentrations up to 500 ng/ml did not increase proliferation of C2C12 cells, primary human myoblasts or primary mouse muscle stem cells, did not delay myoblast fusion, and did not activate p-ERK in cardiac myocytes, although mature IGF-1 and full-length IGF-1Eb did produce a response in the same experiments. The authors wrote that the results call the physiological role of MGF into question. ^[21]
• Animal studyA synthetic 24-amino-acid MGF E-domain peptide improved the engraftment of transplanted human myogenic precursor cells in mice, delivered either into the muscle or systemically. In the dish it increased the precursor cells' proliferation through a mechanism other than binding the IGF-1 receptor. ^[16]
• Animal studyAn E-domain peptide delivered locally to the heart from polymer microrods after coronary artery ligation in mice reduced mortality and slowed the decline in cardiac function, an injury-repair experiment in animals rather than a test of an injected PEGylated product in people. ^[22]

PEG-MGF side effects and risks

No published human study has given anyone PEG-MGF, so there is no human side-effect record for it. What follows is a regulator's assessment and a laboratory finding, not reactions documented in a person.

• Regulator reviewFDA states it has identified no human exposure data on drug products containing PEG-MGF administered by any route, and that it lacks the information needed to say whether the substance would cause harm in people. The same entry flags a significant immunogenicity risk for certain routes and difficulty characterising the active ingredient and its peptide-related impurities. ^[23]
• Lab studyThe concern raised in the published literature is proliferative rather than acute. MGF (IGF-1Ec) was found to be overexpressed in human prostate cancer tissue and cell lines but not in normal prostate epithelial cells, and a synthetic MGF E peptide added to those cancer cells increased their growth and activated ERK1/2 - an effect that silencing the IGF-1 and insulin receptors did not remove. ^[17][24]

Other things to know

• FDA states it has identified no human exposure data for PEG-MGF administered by any route, and separately flags a risk of immunogenicity for certain routes of administration plus complexities with peptide-related impurities and API characterisation.
• Not on the FDA 503A Bulks List, so a pharmacy cannot lawfully compound it; every unit sold to consumers is an unverified research chemical, not a regulated medicine.
• Marketed on the strength of research into a related, naturally occurring splice variant of IGF-1, not on any completed human trial of the PEGylated product itself.
• IGF-1 pathway activity carries a class-level concern around insulin sensitivity and growth signalling that has not been studied for PEG-MGF specifically in humans.
• Prohibited at all times in sport under the WADA 2026 Prohibited List, S2.3 (Mechano growth factors).
• No published human pharmacokinetic study establishes a half-life; treat any figure sold alongside dosing charts as unverified.

Reported side effects and what the studies measured: PEG-MGF side effects.

Where this vial size comes from

PEG-MGF is sold as a 2 mg vial by the pages below, each checked on the date shown. I list them as evidence that this size exists, not as a recommendation to buy from them.

• SwissChemsvendorLists it as: "PEG MGF 2mg"; Total Compound Content: 2 mg per vial · checked 2026-09-28
• Next Level PharmvendorLists it as: PEG-MGF, 2mg size option · checked 2026-09-28

The doses come from the sourced common protocol on the PEG-MGF dosing page, and every number on this page is arithmetic on those doses and this vial size.

Other PEG-MGF vial sizes

• 2 mg
• 5 mg vial

Where to buy PEG-MGF for research

Sold for research use only. Listed by Next Level Pharm and BioEdge Research Labs; compare them on my vendors page or see the listing on the PEG-MGF page.

Questions

How much water do I add to a 2 mg PEG-MGF vial?

There is no single correct amount: water changes how many units a dose is, not how many doses the vial holds. With 1 mL the vial is 2 mg/mL and 300 mcg is 15 units (0.15 mL) on a U-100 insulin syringe. The units table gives 1, 2, 5 mL.

How many doses are in a 2 mg PEG-MGF vial?

10 doses at 200 mcg, 6 doses at 300 mcg, 5 doses at 400 mcg.

How long does a 2 mg PEG-MGF vial last?

At 300 mcg a dose and 2-3 times a week, about 2-3 weeks. How long a mixed vial keeps is a separate limit; see storage below.

How many 2 mg vials do I need for a cycle?

1 vial at 200 mcg 2 times a week for 4 weeks; 4 vials at 400 mcg 3 times a week for 6 weeks.

What does 1 unit equal in a 2 mg PEG-MGF vial?

20 mcg with 1 mL, 10 mcg with 2 mL, 4 mcg with 5 mL of bacteriostatic water, on a U-100 syringe.