Jarrow Formulas R-Alpha Lipoic Acid (Bio-Enhanced Na-rala) exhibits high bioavailability and is the form of alpha lipoic acid found naturally in plants, animals, and the human body. Rala is an antioxidant and a cofactor in cellular energy production, as well as glucose and lipid metabolism. We have included d-Biotin in this formula because it helps to prevent biotin deficiency from long-term alpha lipoic acid use.