You can call it 3,7-dihydro-1,3,7-trimethyl-1H-purine-2,6,-dione OR 1,3,7-trimethylxanthine, but what we are really talking about is CAFFEINE. Caffeine may be the most popular drug in the world. We consume caffeine in coffee, tea, cocoa, chocolate, some soft drinks, and some drugs. The actual source of caffeine is the coffee bean, tea leaf, kola nut and cacao pod. Pure caffeine is odorless and has a bitter taste.