Casein protein is one of the basic stages in the manufacture of nutritional supplements and protein isolates, providing the body with protein. Improve body health. Features of Applied Nutrition Micellar Casein Protein Contains the protein and energy needed to support the growth of muscle mass. Helps reduce muscle catabolism and maintains it during sleep. Rich in essential amino acids. Helps reduce muscle breakdown Contains glutamine, which contributes to the preservation and regeneration of muscles.