Follistatin-344
FST-344 / Myostatin Inhibitor
Myostatin inhibitor studied for exceptional muscle growth by blocking the body's natural muscle-growth limiter. Dramatic animal model results. Significant organ growth safety concerns.
Mechanism of action
Binds and neutralizes myostatin GDF-8 — the protein that limits muscle growth. Also binds activin which has muscle-catabolism effects. Results in substantially increased muscle fiber size and number in animal models. Myostatin knockout animals show dramatic muscle hypertrophy.
Effects in the body
Myostatin is the biological brake on muscle growth. Follistatin releases that brake. Animal models with myostatin knockout show dramatic muscle hypertrophy. Follistatin research tries to replicate this pharmacologically for muscle wasting disease applications.
Pros & cons (from the literature)
- Dramatic muscle hypertrophy in animal models
- Targets a legitimate biological growth limiter
- Studied for DMD sarcopenia and cachexia
- Effects on connective tissue repair also noted
- Organ growth concerns including cardiac and prostate hypertrophy in animal models
- Currently RUO not compoundable
- Human safety data extremely limited
- Difficult to manufacture to high purity
- Long-term effects completely unknown
Protocol summary (from published research)
Dosing ranges reproduced from published research literature. Not a prescription, not medical advice.
FDA & regulatory status
Evidence base
Strong animal data. Human trials limited. Gene therapy approaches more advanced than peptide administration. Mechanistic data compelling but safety profile unclear.
Primary research sources
Peer-reviewed literature referenced throughout this profile is drawn from PubMed, Cell Metabolism, and clinical trial registries cited in the evidence base above.