Dietary Supplement. 1000 mg of Branched Chain Amino Acids per Serving. Optimum Nutrition’s BCAA 1000 Caps provides a 1,000 mg (1 g) blend of the three Branched Chain Amino Acids (L-Valine, L-Leucine, and L-Isoleucine) in every serving. The Branched Chain Amino Acids (BCAA’s), so named because of their unique branched chemical structure, are essential in that the body cannot make them from other compounds. Optimum Nutrition’s BCAA 1000 Caps is produced and packaged in our own state-of-the-art manufacturing facility.