Usn nutrition creatine x4 is a high strength multi stack creatine capsule providing you with an effective 4 in 1 creatine supplementr creatine can be used to support atp levels during muscular contraction creatine works by regenerating your atp this is your bodyrsquos main source of energy once creatine stores in your muscles are depleted your energy levels comes to a haltr usn nutrition creatine x4 also includes l glycine and taurine to help with protein synthesis and make sure muscles