Coenzyme Q10 (CoQ10) is supported by a moderate level of scientific evidence for its role in supporting and treating certain aspects of cardiovascular disease, particularly heart failure and hypertension. CoQ10 is a naturally occurring antioxidant that plays a crucial role in mitochondrial energy production and protecting cells from oxidative damage. Several randomized controlled trials and meta-analyses have reported that CoQ10 supplementation can improve symptoms in people with chronic heart failure, including improvements in ejection fraction and exercise capacity. Notably, the 2014 Q-SYMBIO study, a multicenter randomized trial, demonstrated that CoQ10 supplementation (100 mg three times daily) significantly reduced major adverse cardiovascular events and mortality in patients with chronic heart failure compared to placebo.

Evidence for CoQ10’s use in other cardiovascular conditions, such as hypertension, is mixed but generally positive; some studies have shown modest reductions in blood pressure with supplementation. For other indications like primary prevention of cardiovascular disease or treatment of statin-associated muscle symptoms, the evidence is less definitive. Overall, CoQ10 is considered safe and well-tolerated, making it an attractive adjunctive therapy for certain cardiovascular patients, especially those with heart failure or on statin medications.

In summary, CoQ10 is supported by scientific evidence—though not as strongly as for some conventional therapies—and may offer benefits for specific cardiovascular conditions, particularly heart failure.