Also-called-like-this: Coenzyme Q10
What-it-does: antioxidant

Thanks to Nivea, Q10 is a pretty well-known ingredient and the fame and Beiersdorf's (the parent company of Nivea) obsession with it are not for no reason. It's an antioxidant found naturally in human cells where it plays a big role in energy production.

In fact, it's so important for energy production that if taken as an oral supplement it has a caffeine-like effect and if taken at night you will probably not sleep very well (so you should take it in the morning). Q10 supplementation is not a bad idea: it not only gives you energy but research also shows that oral Q10 increases the Q10 level of the skin (of course, it decreases with age like pretty much every good thing in the skin) and may help to reduce wrinkles. If you are not for supplements, dietary sources include fish, spinach, and nuts.

As for skincare, Q10 comes in the form of a yellow, oil-soluble powder that's shown to absorb into the upper layer of the skin and act there like an awesome antioxidant. It not only has preventative effects but might also be able to reduce the depth of wrinkles, though 0.3% Q10 was used in the study that counts as really high (products containing that much should be very yellow!).