Find over 200 print-friendly fact sheets about heart disease and related health topics.
What is coenzyme Q10?
Q10 (CoQ10) is a substance similar to a vitamin. It is found in every cell of
the body. Your body makes CoQ10, and your cells use it to produce energy your
body needs for cell growth and maintenance. It also functions as an
antioxidant, which protects the body from damage
caused by harmful molecules. CoQ10 is naturally present in small amounts in a
wide variety of foods, but levels are particularly high in organ meats such as
heart, liver, and kidney, as well as beef, soy oil, sardines, mackerel, and
enzymes work to digest food and perform other body
processes, and they help protect the heart and skeletal muscles.
CoQ10 is available in the United States as
a dietary supplement. It is also known as Q10, vitamin Q10, ubiquinone, or
What is CoQ10 used for?
Many claims are made about CoQ10. It is said to help heart failure, as well as cancer,
muscular dystrophy, and
periodontal disease. It is also said to boost energy
and speed recovery from exercise. Some people take it to help reduce the
effects certain medicines can have on the heart, muscles, and other
If you have heart failure, talk
to your doctor before you take any supplement. There's no strong evidence that
vitamins or other supplements can help treat heart
They are used along with medical heart failure treatments, not instead of treatment.
But you may still hear
about CoQ10 supplements and heart failure. CoQ10 has not been shown definitely to relieve heart
failure symptoms. Only some of the studies of coenzyme Q10 showed that it helps heart
In 1961, scientists saw that people with
cancer had little CoQ10 in their blood. They found low CoQ10 blood levels in
people with myeloma,
lymphoma, and cancers of the breast, lung, prostate,
pancreas, colon, kidney, and head and neck. Some research has suggested that
CoQ10 helps the
immune system and may be useful as a secondary
treatment for cancer.
But the National Cancer Institute (NCI) rates the strength
of the evidence for CoQ10 and cancer as weak.2
Research does not
support a helpful effect of CoQ10 in periodontal (gum) disease, muscular
dystrophy, or exercise recovery.
Is CoQ10 safe?
Taking 100 mg a day or more of CoQ10 has caused mild
insomnia in some people. And research has detected
elevated levels of liver enzymes in people taking doses of 300 mg per day for
long periods of time. Liver toxicity has not been reported.
reported side effects include rashes, nausea, upper abdominal pain, dizziness,
sensitivity to light, irritability, headache, heartburn, and fatigue.
high cholesterol (statins) and medicines that lower
blood sugar cause a decrease of CoQ10 levels and reduce the effects of CoQ10
supplements. CoQ10 can reduce the body's response to the blood thinner (anticoagulant) medicine warfarin (Coumadin) and can
decrease insulin requirements in people with
The U.S. Food and Drug
Administration (FDA) does not regulate dietary supplements in the same way it
regulates medicines. A dietary supplement can be sold with limited or no
research on how well it works or on its safety.
Always tell your
doctor if you are using a dietary supplement or if you are thinking about
combining a dietary supplement with your conventional medical treatment. It may
not be safe to forgo your conventional medical treatment and rely only on a
dietary supplement. This is especially important for women who are pregnant or
When using dietary supplements, keep in mind the
CitationsCoenzyme Q10 (2006). Medical Letter on Drugs and Therapeutics, 48(1229): 19–20. National Cancer Institute (2010). Coenzyme Q10. Available online: http://cancer.gov/cancertopics/pdq/cam/coenzymeQ10/healthprofessional/allpages.Other Works Consulted Coenzyme Q10 (2006). Medical Letter on Drugs and Therapeutics, 48(1229): 19–20. Gaby AR, Mischley LK (2006). Coenzyme Q10. In JE
Pizzorno Jr, MT Murray, eds., Textbook of Natural Medicine, 3rd ed., pp. 859–869. Edinburgh: Churchill Livingstone.
June 29, 2011
Adam Husney, MD, MD - Family Medicine & Marc S. Micozzi, MD, PhD - Complementary and Alternative Medicine
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