BCAA 1000 contains a balance of Branched Chain Amino Acids, which are building blocks of muscle mass and size. Metabolized directly in the muscle, BCAAs may improve nitrogen retention by sparing other amino acid groups for repair and rebuilding. The Branched Chain Amino Acids (BCAAs), so named because of their unique branched chemical structure, are essential in that the body cannot make them from other compounds. In recent times, these amino acids have been investigated for their potential anticatabolic (reducing muscle breakdown) and anabolic (muscle building) effects.