Coenzyme Q10, also known as ubiquinone, ubidecarenone, coenzyme Q, and abbreviated at times to CoQ10, CoQ, or Q10 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 free radicals. CoQ10 is naturally present in tiny amounts in a wide variety of foods, but levels are highest in organ meats such as heart, liver, and kidney, as well as beef, soy oil, sardines, mackerel, and peanuts.