Coenzyme Q10 (CoQ10) is a substance found naturally in the body. It helps convert food into energy. CoQ10 is a powerful antioxidant, which fights damaging particles in the body known as free radicals, which damage cell membranes, tamper with DNA, and even cause cell death. Scientists believe free radicals contribute to the aging process, as well as a number of health problems, including heart disease and cancer. Some researchers believe that CoQ10 may help with heart-related conditions, because it can improve energy production in cells, prevent blood clot formation, and act as an antioxidant. Talk your doctor about whether or not you need it, however.