Nature39s plus is the first to offer a 100 pure l tyrosine capsule together with its synergistic partner vitamin b 6 vitamin b 6 is an integral cofactor in the body39s utilization of l tyrosine amino acids the famed building blocks of protein are essential to the formation of muscle tissue and mass they have widespread involvement in a range of bodily functions including efficient brain function and the manufacture of energy available sizes bottles of 60 5153