Ubiquinol

Ubiquinol is the fully reduced, electron-rich form of Coenzyme Q10 that shuttles electrons between Complex I/II and Complex III of the mitochondrial respiratory chain — the central reaction of oxidative phosphorylation that generates 90% of cellular ATP. Unlike ubiquinone (oxidised CoQ10), ubiquinol does not require conversion prior to membrane incorporation, resulting in 3–5× higher plasma levels after oral administration — a critical advantage in older adults whose hepatic reduction capacity is impaired. As a lipid-phase antioxidant anchored within mitochondrial and plasma membranes, ubiquinol regenerates Vitamin E from the tocopheroxyl radical and prevents mitochondrial inner membrane lipid peroxidation. In heart failure patients, CoQ10 supplementation significantly reduced major cardiac events in the Q-SYMBIO double-blind study.