Evidence Level
CoQ10 has a robust evidence base, particularly for cardiovascular applications. The Q-SYMBIO trial (Mortensen et al., 2014) is the landmark study — a multicenter, randomized, double-blind trial of 420 heart failure patients that demonstrated 300mg CoQ10 daily for 2 years significantly reduced major cardiovascular events and mortality. Rosenfeldt et al. (2007) published a comprehensive meta-analysis confirming blood pressure-lowering effects. Littarru and Tiano (2007) provided a thorough review of CoQ10's bioenergetic and antioxidant roles. The ubiquinol vs ubiquinone debate centers on bioavailability — ubiquinol is the reduced, active form and is approximately 2x more bioavailable, making it the preferred form for older adults whose conversion capacity may be diminished.