CoQ10, or Coenzyme Q10, is a compound found naturally in the energy-producing center of the cell known as the mitochondria. CoQ10 assists with the production of an important molecule known as ATP. ATP is the main energy source in the cell, and is critical for many biological processes including muscle contraction and protein production. CoQ10 also boosts energy, enhances the immune system, and acts as an antioxidant. Most of us get enough CoQ10 in our diets. It is found in oily fish, organ meats such as liver and whole grains.