R-Α-lipoic acid (abbreviation: RLA) is a coenzyme present in mitochondria that is like vitamin, which can eliminate free radicals that accelerate aging and pathogenesis. After intestinal absorption into the cells, fat-soluble and water-soluble properties in α-lipoic acid can enable itself to reach any cells within the body to enhance its effectiveness. This makes R- α-lipoic acid such an excellent universal antioxidant. In particular, R- (dextrorotatory) α-lipoic acid has higher physiological activity. In addition, mercapto radical of α-lipoic acid can be easily reversed in redox reaction, so that it can protect thiolase from heavy metal ions.