Coenzyme Q10 is a fat-soluble compound with a chemical structure similar to vitamin K. The "Q10" refers to 10 isoprenoid units attached to a quinone ring. In humans, coenzyme Q10 is most prevalent; in other species, coenzymes Q6, Q7, Q8, and Q9 dominate.
The highest concentrations of endogenous coenzyme Q10 are found in the heart, liver, kidney, and pancreas of humans. There are two physiological forms of coenzyme Q10 that are also available as supplements: the oxidised form (ubiquinone) and the reduced form (ubiquinol).
Preliminary clinical evidence suggests that applying a coenzyme Q10 1% cream to the skin twice daily for 5 months reduces objective wrinkle scores.