The Canadian Consensus Panel on statin adverse effects states that use of coenzyme Q10 (CoQ10) supplements has been associated with small to no benefits, and the existing evidence shows conflicting results. In addition, in their previous document, the group has recommended against using vitamins, minerals, or supplements for statin-associated myalgia symptoms. [1,2]
The European Atherosclerosis Society Consensus does not recommend CoQ10 for the prevention or treatment of statin-associated muscle symptoms (SAMS) based on a randomized clinical trial and a meta-analysis that show no benefits of CoQ10 in SAMS. 
A 2020 meta-analysis assessed randomized controlled trials of oral CoQ10 supplementation versus a placebo in adults with statin-associated myalgia (N= 7 studies; N= 321 participants). No benefit of CoQ10 supplementation in improving myalgia symptoms was found compared to placebo (weighted mean difference −0.42; 95% confidence interval [CI] −1.47 to 0.62). CoQ10 did not improve the proportion of patients remaining on the statin treatment (risk ratio [RR] 0.99; 95% CI, 0.81 to 1.20). This meta-analysis is limited by significant heterogeneity in included studies such as CoQ10 formulation and strength as well as the statin drug and dosing. 
Another meta-analysis published in 2022 assessed eight studies (N= 472 participants) to examine the effect of adding CoQ10 on statin-induced myopathy. The analysis did not reveal a benefit of CoQ10 compared to placebo in improving muscle pain (mean difference,−0.59; 95% CI, −1.54 to 0.36; p= 0.22). Creatine kinase activity increased after adding CoQ10, but the change was not significant (mean difference, 3.29 U/L; 95% CI, −29.58 to 36.17 U/L; p= 0.84). The authors did not conduct a meta-regression due to the dataset being less than 10 studies. Across studies, myalgia scores increased only slightly regardless of the treatment, so the authors postulated that some study participants may not have experienced myalgia severe enough to observe the benefits of supplementing CoQ10. 
Per a review by Backes et al., to improve statin tolerability, one may consider starting CoQ10 two weeks prior to re-starting statin therapy to offset the reduction of endogenous CoQ10 levels, which has been associated with development of myalgia. In addition, a short-term CoQ10 may be used in high cardiovascular risk patients who have experienced intolerance to multiple statins. However, it is noted that routine use of CoQ10 for SAMS is not supported by the literature. Smaller trials have shown conflicting outcomes, and a randomized double-blind controlled trial of high-dose CoQ10 (600 mg daily) showed no benefits of the supplement despite the significant increase in serum CoQ10 levels. 
Natural Medicines Database rates the use CoQ10 for statin-induced myopathy as "inconclusive." 
A pharmacology textbook suggests that the use of statin is associated with lower levels of endogenous coenzyme Q10 and may result in statin-induced myopathy. However, whether a reduction in CoQ10 is a result or a cause of statin-induced myopathy is yet to be determined. Overall, there appears to be a lack of evidence to support the use of CoQ10 to prevent statin-induced myopathy. Moreover, further studies are needed to determine if there are certain patients that may benefit from CoQ10 based on the statin used, the dose of statin, and the duration of therapy. 
A short communication published in 2022 failed to find any benefit for CoQ10 supplementation for SAMs (total N= 511 statin users; n= 64 CoQ10 users). Use of CoQ10 was not significantly associated with resolution of SAMS in multivariate models adjusted for risk factors.