Follistatin vs Mechano Growth Factor (MGF)
Two elegant muscle-growth mechanisms whose most impressive data belong to gene therapy and to your own genes, not to the injectable vials sold under their names.
Follistatin
FST-344
Blocking myostatin drives dramatic muscle growth in mice and primates, but the injectable follistatin peptide has no controlled human efficacy trials.
Full Follistatin evidence reviewMechano Growth Factor (MGF)
IGF-1Ec / PEG-MGF
A real load-induced IGF-1 splice variant in muscle biology, but the injected PEG-MGF product has no controlled human outcome trials.
Full Mechano Growth Factor (MGF) evidence reviewSide by side
| Follistatin | Mechano Growth Factor (MGF) | |
|---|---|---|
| Marketed for | Muscle growth | Muscle growth, recovery |
| Evidence grade | Preclinical / minimal | Preclinical / minimal |
| Family | GH axis | GH axis |
| Regulatory status | Investigational | Not FDA-approved |
| How it's obtained | Research-only | Research-only |
| Key human source | Kota, Sci Transl Med 2009 (primates) | Yang & Goldspink, FEBS Lett 2002 |
marks a row where the two differ. Evidence grades come from our evidence matrix, which grades each molecule on the human data for the use it is marketed for.
Our verdict
Neither injectable has controlled human efficacy data, so the honest comparison is about which borrowed evidence each one leans on. Follistatin sits on a real pathway: it neutralizes myostatin, the body's brake on muscle, and the striking results come from gene therapy, where AAV-delivered follistatin grew muscle and strength in monkeys and reached small, open-label early-phase human trials in Becker muscular dystrophy and inclusion body myositis. The gray-market follistatin-344 peptide is a different proposition, cleared in hours, unable to recreate sustained local expression, and untested in controlled human trials; follistatin also blunts activin and other TGF-beta ligands that do real work outside muscle, so systemic use has unknown long-term safety. MGF's human evidence is likewise displaced: it documents the body's own IGF-1Ec splice variant upregulating after resistance exercise, not anyone injecting PEG-MGF. Both injectables are unapproved research-only material with no established dose.
Follistatin fits if
Follistatin is the more instructive read if you want to see how genuinely serious translational science, in this case gene therapy in an investigational setting, gets repackaged as a consumer vial it never tested.
Mechano Growth Factor (MGF) fits if
MGF is the more instructive read if you want the cleanest example of the endogenous-versus-injected swap, where the real human finding argues for training rather than for buying anything.
Where to get it
Where to get peptide therapy
Clinician-led telehealth services that prescribe compounded peptides. The specific peptides offered vary by provider — confirm Follistatin availability before ordering.
