whey protein isolate is produced from pasteurized whey that has non protein elements removed. Whey is a byproduct in the making of cheese. Once a sufficient amount of non protein components is removed, the resulting protein material is dried. Whey protein isolate contains no less than 90% of pure protein whey protein isolate is a complete protein, which means it has all of the amino acids that are needed in a daily diet. It contains high levels of branched chain amino acids. Branched chain amino acids are unlike other amino acids in the promotion of muscle growth because they can be metabolized directly into muscle tissue.