Overview
Follistatin is a naturally occurring protein that binds and inhibits myostatin (a limiter of muscle growth). It is heavily discussed in muscle-growth contexts, including gene-therapy research.
How It's Thought to Work
By neutralizing myostatin and related factors, follistatin can remove a brake on muscle growth in animal models.
What the Research Says
Most striking results are from animal and gene-therapy studies; human evidence for injectable 'follistatin' products is minimal and their real content is often uncertain.
Regulatory & Legal Status
Not FDA-approved. Sold as a research chemical; product authenticity is a major concern. Prohibited in sport by WADA.
Safety Considerations
Little to no human safety data; unregulated and often misrepresented products. Consult a qualified clinician.