L-LysinePure Encapsulations L Lysine is an essential amino acid supplement containing L Lysine HCl in convenient capsule form. This fundamental building block protein provides targeted support for immune function and tissue health. Each capsule contains L Lysine HCl, an essential amino acid that the body cannot produce on its own. L Lysine plays a crucial role in protein synthesis and helps maintain the balance of amino acids, particularly in relation to