GNC Alpha-Lipoic Acid 300mg supports cell energy metabolism and antioxidant regeneration and is to be taken once daily. Alpha-lipoic acid 600mg helps in the regeneration of antioxidants such as Vitamins E and C and glutathione in the body. Antioxidants are important because they can help minimize cell damage that is caused by excessive production of harmful free radicals. These radicals can destroy healthy cells and affect cell aging, rendering alpha-lipoic acid an important nutrient in combatting these issues.