From the Guidelines

Coenzyme Q10 (CoQ10) supplementation has several benefits, particularly in reducing blood pressure in patients with cardiometabolic disorders.

Reduces systolic blood pressure (SBP): CoQ10 supplementation significantly reduces SBP in patients with cardiometabolic diseases, with a mean decrease of -4.77 mmHg 1.
Increases circulating CoQ10 concentrations: CoQ10 supplementation elevates circulating CoQ10 concentrations, which may contribute to its beneficial effects on blood pressure 1.
More effective in patients with diabetes or dyslipidemia: CoQ10 supplementation is more effective in reducing SBP in patients with diabetes or dyslipidemia, with a mean decrease of -5.80 mmHg and -6.71 mmHg, respectively 1.
Optimal intake: The optimal intake of CoQ10 supplementation for reducing SBP is approximately 100-200 mg/d, with a U-shaped dose-response relation observed between CoQ10 supplementation and SBP level 1.
Antioxidant and anti-inflammatory properties: CoQ10 supplementation has antioxidant and anti-inflammatory properties, which may contribute to its beneficial effects on blood pressure and cardiovascular health 1.

Recommended intake: Based on the available evidence, 100-200 mg/d of CoQ10 supplementation is recommended for attenuating SBP in patients with cardiometabolic disorders 1.
Potential add-on therapy: CoQ10 supplementation may be used as an add-on therapy to conventional treatments for hypertension, particularly in patients with diabetes or dyslipidemia 1.
Further research: Further research is needed to determine the exact mechanisms of CoQ10 supplementation on blood pressure and to establish its long-term safety and efficacy 1.

From the Research

CoQ10 is an essential cofactor in energy metabolism and antioxidant protection, with the highest concentration found in the heart 2.
CoQ10 supplementation has been shown to reduce oxidative stress and mortality from cardiovascular causes, and improve clinical outcomes in patients undergoing coronary artery bypass graft surgery 2.
CoQ10 supplementation can prevent the accumulation of oxLDL in arteries, decrease vascular stiffness and hypertension, and improve endothelial dysfunction by reducing the source of ROS in the vascular system and increasing NO levels for vasodilation 2.
CoQ10 has been found to have beneficial effects on cardiovascular disease, including reducing cardiovascular death in patients with heart failure 3.
CoQ10 supplementation has been suggested as a promising therapeutic agent to prevent and slow the progression of diseases such as metabolic syndrome, type 2 diabetes, neurodegenerative diseases, and male infertility 4.
CoQ10 has anti-inflammatory and antioxidant properties, and may be involved in the prevention of neuronal and muscular degenerative diseases, migraine, and cancer 5.
CoQ10 supplementation may improve functional capacity and reduce cardiovascular events and mortality in patients with heart failure, as seen in the Q-SYMBIO trial 6.

Reduces oxidative stress and inflammation 2, 3, 4
Improves cardiovascular health and reduces mortality from cardiovascular causes 2, 3, 6
May have beneficial effects on neurodegenerative diseases, migraine, and cancer 5
May improve functional capacity and reduce cardiovascular events and mortality in patients with heart failure 6
Has anti-inflammatory and antioxidant properties 5, 4