Educational content only — this is not medical advice. Nothing here is a recommendation to buy, obtain, or use Follistatin-344. Talk to a licensed clinician before making health decisions.
What it is
Follistatin is a naturally occurring glycoprotein that binds and inhibits myostatin and activin. Follistatin-344 refers to a research construct used in gene-therapy experiments to increase follistatin expression. It is not an approved drug and is not the same as endogenous human follistatin.
What the evidence shows
Animal studies, particularly in mice and non-human primates, show large increases in muscle mass with follistatin overexpression. In humans, follistatin gene therapy has been explored in early trials for Becker muscular dystrophy and inclusion-body myositis, but these are experimental, small, and not FDA-approved. No robust RCT supports use in healthy people.
Risks & unknowns
Broad inhibition of myostatin/activin can affect tendons, ligaments, the heart, reproductive organs, and immune function. Animal models have shown tendon weakening and other off-target effects. Long-term safety is unknown, and gene-therapy approaches carry irreversible and systemic risks.
Legal / regulatory status
Follistatin-344 is not FDA-approved. It is prohibited by WADA under S2. Marketing it for human use is illegal.