Discusses Coenzyme Q10 (CoQ10), also known as Q10, vitamin Q10, or ubiquinone. Looks at use to treat heart failure, cancer, muscular dystrophy, and periodontal disease. Covers safety and side effects of dietary supplements.
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.
CoQ10 may keep the antitumor drug doxorubicin from hurting the
Three studies examined the use of CoQ10 along with conventional
treatment for cancer. The three studies contained a total of 41 women with
breast cancer. In each study, the women improved.
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
Like conventional medicines, dietary supplements may cause side
effects, trigger allergic reactions, or interact with prescription and
nonprescription medicines or other supplements you might be taking. A side
effect or interaction with another medicine or supplement may make other health
conditions worse. Always tell your doctor or pharmacist about all dietary
supplements you are taking.
The way dietary supplements are manufactured may not be
standardized. Because of this, how well they work or any side effects they
cause may differ among brands or even within different lots of the same brand.
The form of supplement that you buy in health food or grocery stores may not be
the same as the form used in research.
Other than for vitamins and minerals, the long-term effects of
most dietary supplements are not known.
Coenzyme Q10 (2006). Medical Letter on Drugs and Therapeutics, 48(1229): 19–20.
National Cancer Institute (2012). Coenzyme Q10 (PDQ) – Health Professional Version. Available online: http://cancer.gov/cancertopics/pdq/cam/coenzymeQ10/healthprofessional.
How this information was developed to help you make better health decisions.