Mix of 3 complete proteins PROMIX is a blend of three complete protein sources: whey protein, casein (the other milk protein) and soy protein. A protein is called complete, when it provides the body with all necessary amino acids, including the 9 amino acids (i.e. Histidine, Isoleucine, Leucine, Lysine, Methionine, Phenylalanine, Threonine, Tryptophan, Valine) that are considered essential for life, because the body cannot synthesize them. PROMIX is high in protein, thus it contributes to the maintenance and growth of muscle mass and also to maintenance of normal bones. We added Taurine to the formula.