Supplementation with CoQ10 has potential as a therapeutic measure. Randomized trials have demonstrated a beneficial role for CoQ10 in CHF. This may be related to its roles in providing energy to the heart and as an antioxidant. Its antioxidant function may also prove beneficial in coronary artery disease (CAD). Improvement of endothelial function after CoQ10 treatment may also contribute to the benefit observed in CAD. A favourable effect on hypertension and diabetes, which are major risk factors for CAD may also be responsible. While benefits of CoQ10 supplementation have been documented in literature, larger, randomized, controlled trials are needed for evaluation of its use as a therapeutic agent in CHF and CAD.