Coenzyme Q10 exists in three redox states: Form Name Abbreviation Redox state Oxidized Ubiquinone CoQ10 Oxidized Semiquinone Ubiquinol radical CoQ10•– Intermediate Reduced Ubiquinol CoQ10H₂ Reduced Most supplements = ubiquinol (reduced, antioxidant) BPM31510 = ubiquinone (oxidized) (might raise ROS in cancer cells)