Allmax Essentials Arginine HCI - Considered a semi-essential amino acid. What that means is the body produces Arginine normally, but sometimes the body needs more than is available and Arginine needs to be supplemented. Food sources such as peanuts and almonds are natural sources of Arginine, but for those looking to enhance athletic performance or increase lean muscle mass, it is difficult to derive the amount required by the body in optimal results from food sources.