L-Lysine, available as L-Lysine HCl (hydrochloride), L-Lysine base, and L-Lysine acetate, is an essential amino acid crucial for protein synthesis, tissue repair, and overall metabolic function in the human body. As one of the nine essential amino acids, L-lysine cannot be synthesized by the body and must be obtained through dietary sources or supplements. Its molecular structure and role in supporting collagen production, immune function, and nutrient absorption make it indispensable for various physiological processes.