Ubiquinol is the reduced, active antioxidant form of Coenzyme Q10 (CoQ10). It is produced naturally by our bodies. Ubiquinol protects our body's cells from stress. Coenzyme Q10 is fat soluble and acts similar to a vitamin. Its primary functions include activity as an antioxidant, a membrane stabiliser, and as a co-factor in many metabolic pathways, particularly in the production of adenosine triphosphate (ATP) in oxidative respiration.