Source Naturals BCAA provides support to your body’s muscular systems with a vigorous blend of branched-chain amino acids and supporting B vitamins. Research has shown that during exercise, branched-chain amino acids are metabolized directly in the skeletal muscle—a process that provides robust musculoskeletal fortification when your body needs it the most. Combined with vitamin B-6 and B-12 for optimized protein synthesis, BCAA may also increase energy and reduce occasional fatigue in support of your active lifestyle.*