Coenzyme Q10 (CoQ10) is an antioxidant that your body produces naturally. Your cells use CoQ10 for growth and maintenance.

Levels of CoQ10 in your body decrease as you age. CoQ10 levels have also been found to be lower in people with certain conditions, such as heart disease, and in those who take cholesterol-lowering drugs called statins.

CoQ10 is found in meat, fish and nuts. The amount of CoQ10 found in these dietary sources, however, isn't enough to significantly increase CoQ10 levels in your body.

CoQ10 dietary supplements are available as capsules, chewable tablets, liquid syrups, wafers and by IV. CoQ10 might help prevent or treat certain heart conditions, as well as migraine headaches.

Research on CoQ10 use for specific conditions and activities shows:

• Heart conditions. CoQ10 has been shown to improve symptoms of congestive heart failure. Although findings are mixed, CoQ10 might help reduce blood pressure. Some research also suggests that when combined with other nutrients, CoQ10 might aid recovery in people who've had bypass and heart valve surgeries.
• Diabetes. Although more studies are needed, some research suggests that CoQ10 may help reduce low-density lipoprotein (LDL) cholesterol and total cholesterol levels in people with diabetes, lowering their risk of heart disease.
• Parkinson's disease. Recent research suggests that even high doses of CoQ10 don't seem to improve symptoms in people with Parkinson's disease.
• Statin-induced myopathy. Some research suggests that CoQ10 might help ease the muscle weakness and pain sometimes associated with taking statins.
• Migraines. Some research suggests that CoQ10 might decrease the frequency of these headaches.
• Physical performance. Because CoQ10 is involved in energy production, it's believed that this supplement might improve your physical performance. However, research in this area has produced mixed results.

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.

Possible interactions include:

• Anticoagulants. CoQ10 might make blood-thinning drugs, such as warfarin (Jantoven), less effective. This could increase the risk of a blood clot.