CHALLENGER NUTRITION PROTEIN MATRIX contains whey protein concentrate, other sources of protein, and a punch with up to 130 calories per 35g serving. You’ll also get 23 full grams of protein and essential nutrients with each dose.‡ We’ve designed this protein matrix for health and athletic individuals looking to increase lean muscle mass and build strength faster. It also mixes well, is easy to digest, and has a delicious flavors taste.‡