NOW AAKG 3500 contains Arginine, a conditionally essential amino acid that has a number of vital roles in human biochemistry. Arginine plays a pivotal role in the urea cycle, helping to rid the body of excess ammonia. This amino acid is also important in protein synthesis as well as for the support of healthy immune function. NOW AAKG 3500 has paired Arginine with Alpha-Ketoglutarate, another key player in amino acid metabolism, as well as in energy production vital for getting the most from your workouts.