If you are serious about your physique, you'll seriously want to give this supplement a look. BCAA: The name may sound like the answer to a grade school puzzle, but there's truly nothing puzzling about this powerful supplement. BCAAs, or branched-chain amino acids, are essential nutrients obtained from food sources such as dairy, legumes and meat. There are three main types of BCAAs: Leucine, isoleucine and valine. They can be used to treat numerous diseases, including those affecting the liver.