GNC Pro Performance Creatine Monohydrate is a dietary supplement used both pre- and post-workout that may help improve athletic performance. Creatine, a naturally occurring substance found in muscle cells, converts to creatine phosphate during intense physical activity. Creatine phosphate helps create more ATP, which boosts athletic performance by providing immediate energy for muscles during intense workouts. Creatine monohydrate can help increase lean muscle mass by reducing muscle breakdown during intense athletic activity. 1 tsp. of GNC Creatine Monohydrate 5000mg provides 5g of creatine monohydrate. Helps muscle produce ATP, the energy fuel for quick intense physical activity. Free from many common allergens including dairy, soy, and gluten.