Coffee mug designed with the atomic structure of the caffeine molecule, modelled in Autodesk Maya and rendered in mentalray 

Caffeine is a central nervous system (CNS) stimulant of the methylxanthine. 

Caffeine is a naturally occurring substance found in many plants, including coffee beans and tea leaves. Kola nuts and cacao pods also contain caffeine. Caffeine can also be man-made, and it is added to many of our foods and drinks. Many over-the-counter and prescription medications contain caffeine. According to the U.S. Food and Drug Administration (FDA), about 90 percent of the world’s population ingests some form of caffeine.