Doctor's Best Stabilized R-Lipoic Acid with BioEnhanced® Na-RALA features a top-quality BioEnhanced® Na-RALA, the sodium salt of R-lipoic acid (RLA). Unlike pure RLA, BioEnhanced Na-RALA is a stabilized form of RLA that won't degrade at high temperatures, is more bioavailable than regular RLA and has no solvent residues. Lipoic acid plays an important role in glucose metabolism and energy production. It is both fat and water soluble, so it's known as the "universal antioxidant" that occurs in two forms: "R" and "S." Studies suggest that RLA, the natural form, is more biologically active than the "S" form. This formula is suitable for vegans.