Safety and side effects

CoQ10 supplements appear to be safe and to produce few side effects when taken as directed.

Mild side effects might include digestive problems such as:

• Upper abdominal pain
• Loss of appetite
• Nausea and vomiting
• Diarrhea

Other possible side effects may include:

• Headaches and dizziness
• Insomnia
• Fatigue
• Skin itching or rashes
• Irritability or agitation

The safety of use of CoQ10 during pregnancy and breast-feeding hasn't been established. Don't use CoQ10 if you're pregnant or breast-feeding without your doctor's approval.