Muscle Milk offers quality you can trust. Our Pro Series Gainer protein powder supplement supplies your body with high quality protein to support muscle maintenance, recovery and growth while delivering calories to support gains after exercise and carbs to help replenish fuel stores. ++ It provides a blend of high-quality slow releasing and fast releasing proteins to help increase amino acid levels. These essential amino acids play a role in muscle growth and maintenance of muscle mass. ++ The formula is also NSF Certified for Sport.