CoQ10Ubiquinone / ubiquinol · 4 claims

Q-SYMBIO randomised 420 patients with moderate to severe heart failure to CoQ10 100 mg three times daily or placebo, on top of standard therapy, for two years. The primary composite endpoint — cardiovascular death, hospital stay for heart failure, mechanical support or transplant — occurred in 30 versus 57 patients (p=0.005, HR 0.50, 95% CI 0.32–0.80). Cardiovascular death: 18 versus 34 (HR 0.51). All-cause mortality: 21 versus 39 (p=0.036, HR 0.51, 95% CI 0.30–0.89).

A 2024 meta-analysis of 33 studies found all-cause mortality RR 0.64 (95% CI 0.48–0.85, p=0.002) at GRADE moderate quality, and heart failure hospitalisation RR 0.50 (0.37–0.67).

Two things to hold onto. This is a treatment effect in diagnosed heart failure patients already on optimal therapy — it says nothing about healthy people. And a Cochrane review of the same question exists, which is the appropriate conservative counterweight to a single trial with a striking result.

• RCTMortensen SA, Rosenfeldt F, Kumar A, et al. The effect of coenzyme Q10 on morbidity and mortality in chronic heart failure: results from Q-SYMBIO JACC Heart Fail 2014;2(6):641-649 · 420 patients, 2 years
• MetaEfficacy and safety of coenzyme Q10 in heart failure: meta-analysis of randomized controlled trials BMC Cardiovasc Disord 2024 · 33 studies · GRADE moderate
• RevAl Saadi T, Assaf Y, Farwati M, et al. Coenzyme Q10 for heart failure Cochrane Database Syst Rev 2021;(2):CD008684

Screening 637 studies against strict methodological criteria left 12 randomised placebo-controlled trials with 575 subjects. CoQ10 significantly improved muscle pain (p<0.001), muscle weakness (p=0.006), muscle cramps (p<0.001) and muscle fatigue (p<0.001).

The authors concluded CoQ10 may be a complementary approach to managing statin-induced myopathy. Some inconsistency of benefit was apparent across trials, particularly on subjective muscle pain — which is also the outcome most susceptible to expectation effects.

• MetaQu H, Guo M, Chai H, et al. Effects of coenzyme Q10 on statin-induced myopathy: updated meta-analysis of RCTs 12 RCTs, 575 subjects, from 637 screened · reproduced in JACC review

No reduction in plasma creatine kinase activity was observed after CoQ10 supplementation, in the same analysis that found symptomatic improvement across four separate muscle complaints.

This is worth sitting with. Patients felt better; the blood marker of muscle damage did not move. That is compatible with a real symptomatic benefit through some other route, and it is equally compatible with an expectation effect on self-reported symptoms. The dissociation is the finding.

• MetaQu H, et al. CK outcome within the statin myopathy meta-analysis No CK reduction despite symptomatic improvement

Q-SYMBIO reported improvements in NYHA functional class, visual analogue score and six-minute walk test in both arms at week 16, with no statistically significant difference between groups. There were also no significant differences in heart rate, blood pressure or echocardiographic measurements.

So the trial that produced a halving of two-year mortality showed nothing on how patients felt or performed at four months. Both results come from the same 420 patients. Whatever CoQ10 is doing in heart failure, it does not appear to work by making people feel better in the short term — which is the outcome most consumers would be buying it for.

• RCTMortensen SA, et al. Q-SYMBIO week-16 functional outcomes JACC Heart Fail 2014;2(6):641-649 · between-group differences not significant