1. What is CoQ10?

   CoQ10 is a compound that is made in the body. The Q and the 10 in coenzyme Q10 refer to the groups of chemicals that make up the product. CoQ10 is also known by the following names:

   • Q₁₀.
   • Vitamin Q₁₀.
   • Ubiquinone.
   • Ubidecarenone.

   A coenzyme helps an enzyme do its job. An enzyme is a protein that speeds up
   the rate at which chemical reactions take place in cells of the body. The body’s cells use CoQ10 to make energy needed for the cells to grow and stay healthy. The body also uses CoQ10 as an antioxidant. An antioxidant protects cells from chemicals called free radicals.

   CoQ10 is found in most body tissues. The highest amounts are found in the heart, liver, kidneys, and pancreas. The lowest amounts are found in the lungs. CoQ10 decreases in the body as people get older.

2. How is CoQ10 given?

   CoQ10 is taken by mouth as a tablet or capsule. It may also be given by injection into a vein (IV).

3. Have any laboratory or animal studies been done using CoQ10?

   In laboratory studies, tumor cells are used to test a substance to find out if it is likely to have any anticancer effects. In animal studies, tests are done to see if a drug, procedure, or treatment is safe and effective in animals. Laboratory and animal studies are done before a substance is tested in people.

   Laboratory and animal studies have tested the effects of coenzyme Q10. See the Laboratory/Animal/Preclinical Studies section of the health professional version of Coenzyme Q10 for information on laboratory and animal studies done using CoQ10.

4. Have any studies of CoQ10 been done in people?
   

   There have been few clinical trials that study the use of CoQ10 in patients with cancer.

   A trial of 236 breast cancer patients were randomized to receive either CoQ10 or placebo, each combined with vitamin E, for 24 weeks. The study found that levels of fatigue and quality of life were not improved in patients who received CoQ10 compared to patients who received the placebo.

   A randomized trial of 20 children treated for acute lymphoblastic leukemia or non-Hodgkin lymphoma looked at whether CoQ10 would protect the heart from the damage caused by doxorubicin. The results reported that CoQ10 decreased the harmful effects of doxorubicin on the heart.

   Clinical trials have been limited to small numbers of people, and it is not clear if the benefits reported were from the CoQ10 therapy, other dietary supplements, or standard treatments used before or during the CoQ10 therapy.

5. Have any side effects or risks been reported from CoQ10?

   Reported side effects from the use of CoQ10 include the following:

   • High levels of liver enzymes.
   • Nausea.
   • Heartburn.
   • Headache.
   • Pain in the upper part of the abdomen.
   • Dizziness.
   • Rashes.
   • Unable to fall sleep or stay asleep.
   • Feeling very tired.
   • Feeling irritable.
   • Sensitive to light.

   Importantly, clinical trials that studied the use of CoQ10 to prevent toxic side effects during cancer treatments (for example, chemotherapy and radiation therapy) have not followed patients over the long term to find whether CoQ10 made the treatments less effective.

   A recent observational study in patients with breast cancer suggested that the use of antioxidant supplements, including CoQ10, before and during cancer treatment may be linked with increased recurrence rates and decreased survival.

   It is important to check with health care providers to find out if CoQ10 can be safely used with other drugs. Certain drugs, such as those that are used to lower cholesterol, blood pressure, or blood sugar levels, may decrease the effects of CoQ10. CoQ10 may change the way the body uses warfarin (a drug that prevents the blood from clotting) and insulin.

6. Is CoQ10 approved by the US Food and Drug Administration (FDA) for use as a cancer treatment in the United States?

   The U.S. Food and Drug Administration (FDA) has not approved the use of CoQ10 as a treatment for cancer.

   The FDA does not approve dietary supplements as safe or effective. The company that makes the dietary supplements is responsible for making sure that they are safe and that the claims on the label are true and do not mislead the patient. The way that supplements are made is not regulated by the FDA, so all batches and brands of CoQ10 supplements may not be the same.

Use our clinical trial search to find NCI-supported cancer clinical trials that are accepting patients. You can search for trials based on the type of cancer, the age of the patient, and where the trials are being done. General information about clinical trials is also available.

Complementary and alternative medicine (CAM)—also called integrative medicine—includes a broad range of healing philosophies, approaches, and therapies. A therapy is generally called complementary when it is used in addition to conventional treatments; it is often called alternative when it is used instead of conventional treatment. (Conventional treatments are those that are widely accepted and practiced by the mainstream medical community.) Depending on how they are used, some therapies can be considered either complementary or alternative. Complementary and alternative therapies are used in an effort to prevent illness, reduce stress, prevent or reduce side effects and symptoms, or control or cure disease.

Unlike conventional treatments for cancer, complementary and alternative therapies are often not covered by insurance companies. Patients should check with their insurance provider to find out about coverage for complementary and alternative therapies.

Cancer patients considering complementary and alternative therapies should discuss this decision with their doctor, nurse, or pharmacist as they would any type of treatment. Some complementary and alternative therapies may affect their standard treatment or may be harmful when used with conventional treatment.

It is important that the same scientific methods used to test conventional therapies are used to test CAM therapies. The National Cancer Institute and the National Center for Complementary and Integrative Health (NCCIH) are sponsoring a number of clinical trials (research studies) at medical centers to test CAM therapies for use in cancer.

Conventional approaches to cancer treatment have generally been studied for safety and effectiveness through a scientific process that includes clinical trials with large numbers of patients. Less is known about the safety and effectiveness of complementary and alternative methods. Few CAM therapies have been tested using demanding scientific methods. A small number of CAM therapies that were thought to be purely alternative approaches are now being used in cancer treatment—not as cures, but as complementary therapies that may help patients feel better and recover faster. One example is acupuncture. According to a panel of experts at a National Institutes of Health (NIH) meeting in November 1997, acupuncture has been found to help control nausea and vomiting caused by chemotherapy and pain related to surgery. However, some approaches, such as the use of laetrile, have been studied and found not to work and to possibly cause harm.

The NCI Best Case Series Program which was started in 1991, is one way CAM approaches that are being used in practice are being studied. The program is overseen by the NCI’s Office of Cancer Complementary and Alternative Medicine (OCCAM). Health care professionals who offer alternative cancer therapies submit their patients’ medical records and related materials to OCCAM. OCCAM carefully reviews these materials to see if any seem worth further research.

When considering complementary and alternative therapies, patients should ask their health care provider the following questions:

National Center for Complementary and Integrative Health (NCCIH)

The National Center for Complementary and Integrative Health (NCCIH) at the National Institutes of Health (NIH) facilitates research and evaluation of complementary and alternative practices, and provides information about a variety of approaches to health professionals and the public.

CAM on PubMed

NCCIH and the NIH National Library of Medicine (NLM) jointly developed CAM on PubMed, a free and easy-to-use search tool for finding CAM-related journal citations. As a subset of the NLM’s PubMed bibliographic database, CAM on PubMed features more than 230,000 references and abstracts for CAM-related articles from scientific journals. This database also provides links to the websites of over 1,800 journals, allowing users to view full-text articles. (A subscription or other fee may be required to access full-text articles.)

Office of Cancer Complementary and Alternative Medicine

The NCI Office of Cancer Complementary and Alternative Medicine (OCCAM) coordinates the activities of the NCI in the area of complementary and alternative medicine (CAM). OCCAM s