Arginine

L-Arginine (Arginine) is a conditionally essential amino acid, meaning it is not usually essential, except in times of illness and stress or for vulnerable populations. Generally, your body will manufacture all of the arginine it needs to function, and arginine can be obtained through most protein-rich foods, including fish, meat, poultry, whole grains, soy products and dairy.  

 As an amino acid, arginine participates in protein synthesis. Still it has other functions and benefits, including acting as the endothelium-derived relaxation factor (EDRF) or a vasodilator, due to its role in the production of nitric oxide. This can redirect or change blood flow depending on needs and can only be done in oxygen-rich conditions.