Overview

• Coenzyme Q ₁₀ is a compound that is made naturally in the body. The body uses it for cell growth and to protect cells from damage that could lead to cancer (see Question 1).

• Animal studies have shown that coenzyme Q₁₀ helps the immune system work better and makes the body better able to resist certain infections and types of cancer (see Question 5).

• Clinical trials have shown that coenzyme Q₁₀ helps protect the heart from the damaging side effects of doxorubicin, a drug used to treat cancer (see Question 6).

• In 3 small studies of coenzyme Q₁₀ in breast cancer patients, some patients appeared to be helped by the treatment. Weaknesses in study design and reporting, however, made it unclear if benefits were caused by the coenzyme Q₁₀ or by something else (see Question 6).

• Coenzyme Q₁₀ may not mix safely with other treatments. It is important that patients tell their health care providers about all therapies they are currently using or thinking of using (see Question 7).

• Coenzyme Q₁₀ has not been carefully tested in combination with chemotherapy to see if it is safe and effective. Because coenzyme Q₁₀ is sold as a dietary supplement rather than a drug, it is not regulated by the US Food and Drug Administration (see Question 8).