How many studies support Coenzyme Q10?

Meta-analyses spanning from 1997 through a 2014 Cochrane review find CoQ10 supplementation can modestly improve symptoms and some outcomes in heart failure, though a 2022 health-technology assessment concluded the evidence is not yet strong enough to firmly establish cost-effective clinical benefit for reduced-ejection-fraction heart failure specifically. That's backed by 8 published studies in Vitaebase's database, including 8 meta-analyses, the most recent from 2025 -- a fairly substantial body of research for a single topic.