Casein protein are most commonly found in mammalian milk, making up 80% of the proteins in cow milk and 20% to 45% of proteins from human milk. Casein has a wide variety of uses, from being a major component of cheese, food additive anda binder for safety matches. As a food source, It supplies amino acids, carbohydrates, and the two inorganic elements calcium and phosphorus. This pool of amino acids is high in essential aminos, which are responsible for muscle protein synthesis. Casein forms a clot in the stomach which slows down the rate of gastric emptying, which also affects the rate of amino acids absorbed from the blood stream. In other words, because of this clot, the casein takes more time to get digested in the stomach, which slows down the amount of amino acids being released into the small intestine where they are absorbed. The casein protein supplements are milk protein and calcium caseinate.