How Caffeine Works

Around 90 percent of Americans consume caffeine every single day in one form or another. More than half of all American adults* consume more than 300 milligrams (mg) of caffeine every day, making it America's most popular drug by far. Caffeine is a natural component of chocolate, coffee and tea, and is used as an added energy boost in most colas and energy drinks. It’s also found in diet pills and some over-the-counter pain relievers and medicines.