Drug Database - Coenzyme Q10 (CoQ10)

Other Names: Coenzyme Q10, Co Q10, Ubiquinone, Vitamin Q

Classification: Dietary Supplement

Coenzyme Q10 (CoQ10) is produced by the human body and is necessary for the basic functioning of cells. CoQ10 levels are reported to decrease with age and to be low in patients with some chronic diseases such as heart conditions, muscular dystrophies, Parkinson's disease, cancer, diabetes, and HIV/AIDS. Some prescription drugs may also lower CoQ10 levels.

Levels of CoQ10 in the body can be increased by taking CoQ10 supplements, although it is not clear that replacing "low CoQ10" is beneficial. CoQ10 has been used, recommended, or studied for numerous conditions, but remains controversial as a treatment in many areas.

These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.

• Coenzyme Q10 Deficiency
  Coenzyme Q10 is normally produced by the human body, although deficiency may occur in patients with impaired CoQ10 biosynthesis due to severe metabolic or mitochondrial disorders, not enough dietary CoQ10 intake, or too much CoQ10 use by the body. Depending on the cause of CoQ10 deficiency, supplementation or increased dietary intake of CoQ10 and the vitamins and minerals needed to produce CoQ10 may be effective.


• High Blood Pressure (Hypertension)
  Preliminary research suggests that CoQ10 causes small decreases in blood pressure (systolic and possibly diastolic). Low blood levels of CoQ10 have been found in people with hypertension, although it is not clear if CoQ10 "deficiency" is a cause of high blood pressure. Well-designed long-term research is needed to strengthen this recommendation.


• Age-Related Macular Degeneration
  Early study shows that acetyl-L-carnitine, n-3 fatty acids, and Coenzyme Q10 (Phototrop®) may help age-related macular degeneration. More research is needed using Coenzyme Q10 alone before a recommendation can be made.


• Alzheimer's
  Promising preliminary evidence suggests that CoQ10 supplements may slow down, but not cure, dementia in people with Alzheimer's disease. Additional well-designed studies are needed to confirm these results before a firm recommendation can be made.


• Angina (chest pain from clogged heart arteries)
  Preliminary small human studies suggest that CoQ10 may reduce angina and improve exercise tolerance in people with clogged heart arteries. Better studies are needed before a firm recommendation can be made.

The below doses are based on scientific research, publications, traditional use, or expert opinion. Many herbs and supplements have not been thoroughly tested, and safety and effectiveness may not be proven. Brands may be made differently, with variable ingredients, even within the same brand. The below doses may not apply to all products. You should read product labels, and discuss doses with a qualified healthcare provider before starting therapy.

Adults (above 18 years old)

• 50-1,200 milligrams of CoQ10 have been taken in divided doses by mouth daily.


• 85 milligrams of CoQ10 per milliliter of soybean oil suspension has been applied to the surface of affected areas once weekly using a plastic syringe for gum disease.


• Most studies of CoQ10 for heart protection during bypass surgery have used CoQ10 taken by mouth. One study used intravenous CoQ10, 5 milligrams per kilogram of body weight, given two hours prior to surgery. Safety is not clear. Any therapies used close to the time of surgery should be discussed with the surgeon and a pharmacist prior to starting.

Children (under 18 years old)

There is not enough scientific information to recommend the safe use of CoQ10 in children. A qualified healthcare provider should be consulted before considering use.

The U.S. Food and Drug Administration does not strictly regulate herbs and supplements. There is no guarantee of strength, purity or safety of products, and effects may vary. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy. Consult a healthcare provider immediately if you experience side effects.

There are few serious reported side effects of CoQ10. Side effects are typically mild and brief, stopping without any treatment needed. Reactions may include:

• nausea
• vomiting
• stomach upset
• heartburn
• diarrhea
• loss of appetite
• skin itching
• rash
• insomnia
• headache
• dizziness
• itching
• irritability
• increased light sensitivity of the eyes
• fatigue
• or flu-like symptoms

CoQ10 may lower blood sugar levels. Caution is advised in patients with diabetes or hypoglycemia, and in those taking drugs, herbs, or supplements that affect blood sugar. Serum glucose levels may need to be monitored by a healthcare provider, and medication adjustments may be necessary.

Low blood platelet number was reported in one person taking CoQ10. However, other factors (viral infection, other medications) may have been responsible. Lowering of platelets may increase the risk of bruising or bleeding, although there is a lack of known reports of bleeding from CoQ10. Caution is advised in people who have bleeding disorders or who are taking drugs that increase the risk of bleeding. Dosing adjustments may be necessary.

CoQ10 may decrease blood pressure, and caution is advised in patients with low blood pressure or taking blood pressure medications. Elevations of liver enzymes have been reported rarely, and caution is advised in people with liver disease or taking medications that may harm the liver. CoQ10 may lower blood levels of cholesterol or triglycerides. Thyroid hormone levels may be altered based on one study.

Organ damage due to lack of oxygen/blood flow during intense exercise has been reported in a study of patients with heart disease, although the specific role of CoQ10 is not clear. Vigorous exercise is often discouraged in people using CoQ10 supplements.

There is not enough scientific evidence to support the safe use of CoQ10 during pregnancy or breastfeeding. Sperm may be affected.