Alpha lipoic acid has many functions, but the main one is to eliminate free radicals and is the only known acid that easily reaches the brain. It also has the ability to regenerate other antioxidants such as vitamins C & E, and glutathione. Therefore, when these antioxidants are depleted, it helps to regenerate them. It also recycles coenzyme Q10 and NAD (nicotinamide adenine dinucleotide).
It is used for the treatment of diabetes because it improves sensitivity to inulin, as a metal chelator, for autoimmune diseases, decreases inflammation and serves in anti-aging therapies.