Also called Pegylated Mechano Growth Factor, PEGylated MGF, IGF-1Ec / IGF-1Eb E-peptide (pegylated)
A longer-lasting lab copy of a muscle signal, with almost no proof in people.
When a muscle is worked hard or hurt, it makes a short signal called MGF, which normally breaks down within minutes. PEG-MGF is a lab-made version with an extra chain (PEG) attached so it lasts longer in the body. It has never been tested in human trials.
The theory is that MGF wakes up the muscle's repair cells and gets them to multiply and build new muscle fiber. The PEG chain is meant to keep it around long enough to reach your muscles from a shot under the skin. Whether MGF really does any of this is disputed.
Mostly animal studies
Weak. The lab that named MGF reported good early results in cells, but a careful repeat by researchers at two drug companies found no effect on human or mouse muscle cells. No one has studied PEG-MGF in people, so the right dose, safety and benefit are all unknown.
Why: The PEG chain is thought to make it last for days, so people use it a few times a week instead of daily. Taking it after training is meant to match when your body makes MGF on its own. None of this has been tested in people.
Start at the low end, and change one thing at a time. If you take medication or have a health condition, check with a doctor first.
Set up for a 2 mg vial. Change any number to match yours. New to this? Read how to mix a vial and mg vs mL vs units first.
Pick your dose and how long you'll run it. We'll count what you need.
Get help right away for swelling of the face or throat, trouble breathing, chest pain, or a spreading, hot, red injection site.
Powder: fridge or freezer. Once mixed with bacteriostatic water: fridge, use within about 3–4 weeks.
FDA: Not approved for any use and never tested in human trials. FDA flagged PEG-MGF for safety concerns in compounding reviews in 2023; its compounding status is still under review, so check current rules.
Sport (WADA): Prohibited at all times (S2, growth factors). Mechano growth factors are named on the list.
It's the same peptide, but PEG-MGF has a PEG chain attached so it doesn't break down within minutes. That's why PEG-MGF is used a few times a week, while plain MGF, if used at all, gets injected right into a muscle after training.
No. The early good results came from cells in a dish, and a careful repeat by two drug companies found no effect. There are no human studies.
Last checked 2026-10