Coenzyme Q10 (CoQ10)

ByLaura Shane-McWhorter, PharmD, University of Utah College of Pharmacy
Reviewed/Revised Mar 2024
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Coenzyme Q10 (ubiquinone) is an enzyme that is naturally produced in the body. Cells use it to produce and manage energy. It also has an antioxidant effect. Antioxidants protect cells against damage by free radicals, which are highly chemically active by-products of normal cell activity.

The levels of coenzyme Q10 seem to be lower in older adults and in people with chronic diseases, such as heart problems, cancer, Parkinson disease, diabetes, HIV infection or AIDS, and muscular dystrophies. However, it is not known whether these low levels contribute to these disorders.

  • In addition to being naturally made in the body, coenzyme Q10 is in foods such as meat, fish, and vegetable oils.

  • A synthetic form of coenzyme Q10 is available as a dietary supplement.

(See also Overview of Dietary Supplements.)

Claims for CoQ10

Coenzyme Q10 is said to be useful because of its antioxidant effect and role in energy metabolism. Antioxidants protect cells against damage by free radicals, which are highly chemically active by-products of normal cell activity.

Proponents claim coenzyme Q10 (CoQ10) improves skin appearance, exercise performance, fertility, brain and lung health, and migraines. Specifically, it is said to benefit people with

Evidence for CoQ10

Because people with some diseases have reduced levels of coenzyme Q10, scientists have studied whether coenzyme Q10 supplements have health benefits. These studies are not conclusive. Some preliminary studies suggest coenzyme Q10 may possess protective properties, but more testing is needed.

  • A 2014 review of 7 studies concluded there was no evidence to support or disprove the benefits of CoQ10 for heart failure; in contrast, a 2017 analysis of 14 trials stated that CoQ10 users had greater exercise capacity and lived longer than those treated with a placebo.

  • Coenzyme Q10 has also been studied as a drug to help relieve muscle problems (including statin-related muscle problems), weakness, cramps, and soreness, but its effectiveness is not clear.

Side Effects of CoQ10

Side effects are uncommon, but some people have

  • Digestive symptoms, such as abdominal pain, nausea, heartburn, diarrhea, and vomiting

  • Central nervous system symptoms, such as dizziness, light sensitivity, irritability, and headache

  • Skin itching

  • Rash

  • Loss of appetite

  • Fatigue

  • Flu-like symptoms

Drug Interactions with CoQ10

Coenzyme Q10 supplements may interact with some antihypertensive (those that lower blood pressure) and chemotherapy drugs.

Recommendations for CoQ10

Coenzyme Q10 appears reasonably safe.

More Information

The following English-language resource may be useful. Please note that THE MANUAL is not responsible for the content of this resource.

  1. National Institutes of Health's National Center for Complementary and Integrative Health: Coenzyme Q10

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