Co-Enzyme Q10 (CoQ10), also known as Ubiquinone, is a vitamin-like substance naturally found in almost every cell in the body. Located in the mitochondria, the powerhouses of our cells, the highest concentration of CoQ10 is in the heart and liver. Co-Enzyme Q10 is a supplement for all adults. It may be helpful for those with heart ailments and chronic fatigue syndrome, as well as for individuals with compromised immune systems.