Easily digestible Vegetarian protein source, well tolerated by individuals with food sensitivities.{9} Builds Muscle Mass† Studies show whey protein is excellent for building muscle mass in combination with resistance training{10} Source of whole food protein Whey protein provides all nine essential amino acids that your body cannot create and is considered a complete protein source. Packed with BCAA’s Great source of branched-chain amino acids, especially arginine — which promotes healthy blood flow and heart health — and leucine, isoleucine and valine — which promote muscle growth.