Branched Chain Amino Acids (BCAA), 240 Capsules, NOW FoodsNOW Branched Chain Amino Acids Dietary Supplement. Pharmaceutical Grade (USP). NOW Branched Chain Amino Acids (BCAA's) are 3 essential amino acids which are abundant in muscles. The branched chain amino acids Leucine, Isoleucine and Valine are three of the eight essential amino acids that the human body must receive in food. These amino acids cannot be synthesized in the liver. Supplement Facts Serving Size: 4 Capsules Servings Per Container: 60