Lentils contain a variety of amino acids, and are a good source of several essential amino acids.
Lentil protein, typical of pulse proteins, is a good source of the essential amino acids leucine, lysine, threonine, and phenylalanine. However, lentils are deficient in the sulfur-containing essential amino acids methionine and cysteine. Therefore, lentils are typically paired with grains to create a more complete protein source.