What does Follistatin-344 do? Benefits and evidence

Follistatin binds signals that limit muscle growth. Human benefit studies delivered a follistatin gene, not protein from a vial. Small gene-therapy studies and an uncontrolled plasmid report cannot establish safe bodybuilding doses. Eleven men developed retinal fluid leakage after reported high-dose protein injections. Online products often contained the wrong material.

• In a small gene-therapy study, four of six people with a muscle disease walked farther; this used a gene, not vial protein. (Studied in a trial)
• Gene therapy versions are being studied for muscle loss with aging; no lifespan benefit has been shown. (Studied in a trial)
• In an animal study, delivering the follistatin gene made thigh muscles larger. (animal)
• People report muscle fullness, strength and growth, but none of it was checked in a controlled way. (Reported by users)

Uses in the sources

• Gene delivery was studied in muscle disease. Myositis benefit is disputed; these findings cannot validate protein-vial use. (Studied in a trial) (source)
• People inject products labeled follistatin-344 for muscle growth. No controlled human trial establishes benefit or a dose for those products. (Reported by users) (source)
• Plasmid and AAV gene therapies are being studied for aging-related muscle decline. No lifespan benefit has been established. (Studied in a trial) (source)