Amino acids are the building blocks of protein molecules,
relatively simple natural substances that are the first
breakdown products of the digestion of proteins. There is no
need to take mixtures of amino acids as nutritional supplements,
no matter what fitness instructors, bodybuilders, and athletes
tell you. If you eat adequate protein, you will have all the
amino acids you need and probably more. Single amino acids are
another matter. There are some single amino acids that have been
used to treat various health problems. These include
L-tryptophan, L-arginine, L-lysine, among others. Take single
amino acids for treatment of particular conditions. Take them
only on an empty stomach and stop using them if you do not
notice any beneficial effects after a reasonable trial, say two
to four weeks.