There are more than 50 Amino Acids which have been identified by scientists and each is a little different. Amino Acids are used to build protein Ð protein helps to support the maintenance of muscle mass and normal bones. Although 50 amino acids have been identified, only 20 of them are used by the human body. Of these 20 amino acids, 9 are classed as Essential Amino Acids. L-Lysine is one of the essential Amino Acids.