You can get even more out of every workout session when you make GNC AMP Mass XXX with MyoTor a part of your exercise routine. This protein-packed dietary supplement is clinically proven to help increase lean muscle mass with 40% fewer sets.* Enhanced with with MyoTOR for improved strength & stamina*, plus, a Creatine Blend to help support athletic performance* and muscle protein synthesis*, while micronized amino acids support key processes crucial to muscle growth and repair.*