Bio-Synergy Performance l-arginine is an effective performance product. Bio-Synergy Performance l-arginine Each tub provides 125, 500mg high strength capsules. Amino acids L-arginine is one of 20 amino acids that the body requires for optimum health. Research Researchers at the University of Exeter discovered taking a dietary supplement of L-arginine may enhance the production of nitric oxide in the body which can significantly boost stamina during high-intensity exercise. The study, published in the August 2010 Journal of Applied Physiology, suggests taking the supplement can allow athletes to exercise up to 20 percent longer.