CoQ10 or ubiquinone is a naturally occurring fat-soluble quinone that is an excellent antioxidant. Its greatest concentration is in the mitochondria where energy is made for every cell in the body. The heart has very high-energy demands and a very high concentration of CoQ10. Research has shown that heart patients tend to be deficient in CoQ10 and intravenous replenishing can be especially useful in the treatment of congestive heart failure. Oral administration of CoQ10 has not been found to be effective to facilitate the uptake of CoQ10 by target tissue, as it is necessary to raise blood levels aggressively. Effective levels can be achieved using intravenous CoQ10, which has been used to support the treatment of cancer, mitochondrial disease and heart disease. Injectable CoQ10 has been found to support energy production, performance enhancement, improved cognition, appearance of skin, and as a cardio-protective agent. Deficiencies are caused by age, poor internal production, poor intestinal absorption, higher than normal use from intense exercise, and certain drugs such as cholesterol lowering medications.