Follistatin 344

Myostatin-binding analog studied for muscle hypertrophy by removing the genetic "growth brake."

Your body caps how much muscle you can build using a protein called myostatin — the genetic "brake pedal" on growth. Follistatin binds and neutralises myostatin, effectively lifting your foot off that brake, which in animal models produces dramatic, rapid muscle gain. It's one of the most powerful anabolic concepts in the catalogue — and one of the least proven in humans. The risks below (tendons that can't keep pace with the new muscle, possible heart-muscle overgrowth, very high cost) are exactly why it stays firmly in experimental territory.