It is found naturally in the leaves, seeds, and fruits of more than 60 plants, including tea leaves, kola nuts, coffee, and cocoa beans. It is in coffee, tea, chocolate, cocoa and many carbonated beverages such as colas. It can also be produced synthetically.
Caffeine has no flavor and can be removed from a food by a chemical process called decaffeination.
Caffeine is absorbed very quickly from the gastrointestinal tract and then distributed in the various body tissues. After absorption, it passes into the central nervous system . This amount will vary from person to person. Caffeine does not accumulate in the bloodstream nor is it stored in the body. It is excreted in the urine many hours after it has been consumed.