Sodium R-alpha-lipoic acid is a highly bioavailable and stabilized form of R-lipoic acid. Regular R-lipoic acid is heat sensitive and may polymerize extensively, decreasing its absorption significantly. In real-time stability tests, sodium R-lipoic acid remained stable for 12 months. The natural R isomer of alpha-lipoic acid may provide enhanced antioxidant activity, while supporting energy production and general metabolic function. Studies suggest that R-lipoic acid promotes glucose metabolism in skeletal muscle. A University of California Berkeley study indicates that R-lipoic acid may be protective against age-related oxidative stress in the liver. Furthermore, a study at Oregon State University established a potential role for R-lipoic acid in protecting the heart from age related oxidative stress.