he main protein source in One Stop Xtreme in an EU sources grass-fed dairy protein blend. Made from preferentially selected undenatured ultra filtered whey protein & undenatured native milk protein providing a valuable source of micellar casein. It provides a very rich source of branched-chain amino acids, essentail amino acids & glutamine. No serious all-in-one bodybuilding supplement would be complete without the following highly popular & highly acclaimed amino acids; pure free form L-leucine; Beta-Alanine; Betaine Anhyrdous & Taurine.