Quest's Amino Acid Series includes a wide range of amino acids, individually or in a complex. Amino acids are the structural elements of proteins, so they are considered to be very important components for the body's functioning. Their supplementation is mainly recommended for vegetarians and athletes. Quest's amino acid products contain "free form" amino acids - which are well absorbed by the body and the brain and are ideal for those with digestive problems. All products of the Amino Acids series contain the L-form of amino acids, that is, the form in which they exist in nature. Only L-form amino acids are linked together to produce proteins.