Of the few hundred amino acids found in nature, 20 are necessary for protein creation and growth, and only 10 of those 20 can be produced by the body. The remaining 10 are known as “essential” amino acids because humans must consume them for proper health. Amino acid deficiencies cause a degradation of internal cells and can lead to huge problems, so it’s important to get enough of them in your diet.
Essential amino acids are most often stereoisomers, meaning they exist in two variations that are identical to one another as mirror images. There are both D- and L- forms of these amino acids, and the L- form is used in protein synthesis and therefore the form found in food and supplements. Because of this, most people simply refer to this nutrient as “lysine” for short.