Whey protein is fast-digesting, meaning the proteins empty from the stomach quickly, resulting in a rapid and substantial increase in amino acids, which aids in muscle synthesis. Casein protein, however, is slow-releasing. Casein consumption results in a prolonged increase in blood amino acids, which reduces muscle breakdown. Both whey and casein have nutritional advantages and are important for muscle health. The composition of the total protein in MPCs is approximately 80-82% casein and 18-20% whey.