An amino acid composed of two bonded acid (alanine and histidine) l-carnosine is a dipeptide found naturally in the body. The main concentrations are in the brain tissue, skin, muscles, kidneys, stomache, and heart. Naturally these levels decline with age, but can be offset with supplements. Because this amino acid shows the ability to prevent glycosylation (cross linking of proteins with sugars to form advanced glycosylation end products/AGEs). It has been suggested that carnosine may beneficial in fighting neuropathy, aging, kidney failure, and diabetes. No serious side effects have been observed in clinical trials, with dosing around 100-500 mg daily.