A Natural Supplement Lipoic acid comes in two forms that are identical in everything but their orientations, like a left and right hand. While natural R-lipoic acid has many health benefits, the artificial S (-) form is useless at best and antagonistic at worst. A Powerful Antioxidant R-lipoic acid is a powerful antioxidant that protects brain and nerve cells from free radicals. It reduces the buildup of iron in the brain which is thought to contribute to Parkinson’s disease. It also supports healthy blood sugar metabolism to prevent insulin resistance. S (-) lipoic acid does not have these benefits and in some cases even thwarts them. Keep Away from the Negative (-) Half Conventional lipoic acid supplements are a 50/50 mixture of R (+) and S (-) forms. AOR’s formula is designed to deliver all the benefits of R-lipoic acid without interference from its “evil twin”.