Coenzyme Q10 (CoQ10) is a compound found naturally in virtually every cell in the human body. Because of its ubiquitous presence in nature and its quinone structure (similar to that of vitamin K), CoQ10 is also known as ubiquinone. CoQ10 is a fat-soluble substance whose primary role is as a vital intermediate of the electron transport system in the mitochondria. Adequate amounts of CoQ10 are necessary for cellular respiration and ATP production. CoQ10 also functions as an intracellular antioxidant. True deficiency states are rare but often present with severe health consequences. Numerous disease processes, linked to low levels of CoQ10, can benefit from CoQ10 supplementation including cardiovascular disease, Parkinson’s disease, muscular dystrophy, breast and other cancers, diabetes mellitus, male infertility, acquired immunodeficiency syndrome (AIDS), asthma, thyroid disorders, and periodontal disease.