essential amino acids

Last reviewed 07/2022

Essential amino acids are those which are mandatory for normal growth and development but cannot be synthesized or are synthesized too slowly for normal requirements. Therefore, essential amino acids must be obtained from the diet.

The group includes:

  • histidine
  • isoleucine
  • leucine
  • lysine
  • methionine
  • phenylalanine
  • threonine
  • tryptophan
  • valine

In the absence of their respective precursors phenylalanine and methionine from the diet, tyrosine and cysteine may become essential.