WHAT ARE BRANCHED CHAIN AMINO ACIDS? BULK POWDERS™ Branched Chain Amino Acids (BCAAs) combine Leucine, Isoleucine & Valine in a 2:1:1 ratio. BULK POWDERS™ Branched Chain Amino Acids (BCAAs) use only 100% pure Leucine, Isoleucine & Valine. BCAAs are considered essential in that they are not produced by the body & must be obtained through our diet. If they are not present in our diet, we would be unable to survive. BCAAs comprise about 1/3 of the protein within our muscles and