●	CoQ10 shows very few significant side effects, though some patients report insomnia and restlessness when treated with high doses of CoQ10 supplements. If this occurs, the dose should be lowered until the symptoms resolve. No serious side effects have been reported from the use of coenzyme Q10. Some patients using CoQ10 have experienced other possible side effects include rashes, nausea, upper abdominal pain, dizziness, visual sensitivity to light, irritability, headache, heartburn, and fatigue. Generally CoQ10 is well tolerated.