Does CoQ10 help your heart or your energy levels?

CoQ10 is a substance your body produces on its own, and it does two things: it helps your cells generate energy and protects them from damage caused by free radicals. That combination makes it interesting for the heart, where both processes play a role in disease.

The evidence is strongest for the heart. A meta-analysis of multiple randomised trials¹ found that CoQ10 supplementation reduced mortality in people with cardiovascular disease by around 32%. The margin around that figure is still fairly wide, but the direction is consistently positive. The same analysis also showed improvements in blood pressure, blood lipids and inflammatory markers.

Specifically in heart failure, a review of 28 trials² found that CoQ10 in the form of ubiquinone reduced hospital admissions and mortality in heart failure patients. Interestingly, the so-called 'superior' form ubiquinol did not show that effect. Worth noting: one of the authors of that review works for a company that sells CoQ10, so keep that potential conflict of interest in mind.

For boosting energy in healthy people or older adults, the evidence is much thinner. There are indications that CoQ10 may help in rare mitochondrial diseases (conditions in which energy production inside cells does not function properly) and with age-related complaints, but large, well-designed studies are lacking³. The popular claim that CoQ10 gives your energy a boost if you are a healthy person? That is simply not well supported.

There is little reason to worry about safety: no serious side effects have been reported at normal doses. CoQ10 is generally well tolerated. A link with Alzheimer's disease has been suggested, but clinical evidence for this is entirely absent.