Ubiquinol

Ubiquinol is the reduced, dihydro form of coenzyme Q10 (CoQ10H2). It is a lipid-soluble compound that participates in mitochondrial energy production as part of the CoQ10 redox cycle. In the mitochondrial electron transport chain, ubiquinone accepts electrons from Complex I and II to become ubiquinol, which then donates electrons to Complex III and is oxidized back to ubiquinone. Beyond its role in respiration, ubiquinol acts as an intracellular antioxidant, protecting lipids and membranes from oxidative damage and helping regenerate other antioxidants such as vitamin E.

Ubiquinol is produced endogenously and can also be obtained from dietary sources, including fatty fish, organ meats, and some whole grains, though dietary amounts are relatively small. Supplements marketed as ubiquinol claim improved absorption compared with ubiquinone, the oxidized form. Some studies have reported higher plasma CoQ10 levels after ubiquinol supplementation, especially in older adults, but the clinical benefits for cardiovascular health, fatigue, or statin-associated symptoms remain uncertain and require further study.

Statins can lower endogenous CoQ10 levels, which has led some clinicians to recommend ubiquinol supplementation to mitigate muscle symptoms, though evidence for symptom relief is inconsistent. Ubiquinol is generally well tolerated; high doses may cause mild gastrointestinal upset or headaches. As with any supplement, individuals taking anticoagulants or with chronic health conditions should consult a healthcare provider before use.