Follistatin: Benefits & Research

Follistatin's primary researched benefit is neutralizing myostatin — the body's natural brake on muscle growth. Myostatin-knockout animals exhibit dramatically increased muscle mass (up to 2× normal). Follistatin achieves pharmacological myostatin inhibition by binding myostatin with nanomolar affinity, preventing it from activating ActRIIB receptors on muscle cells.

By removing myostatin's growth-limiting signal, follistatin allows muscle satellite cells to proliferate and existing fibers to hypertrophy beyond normal physiological limits. Gene therapy studies (AAV-follistatin) in muscular dystrophy patients showed increased muscle mass and improved functional outcomes.

Follistatin's inhibition of activin and other TGF-β superfamily members has anti-fibrotic implications. Activin promotes fibrosis in multiple organs. Follistatin-mediated activin neutralization may reduce fibrotic tissue deposition in muscle, liver, and other organs.