Caffeine is a psychoactive (mind-altering) drug that affects how you think and feel. It is a stimulant that speeds up your breathing, heart rate, thoughts and actions. It’s found in coffee, tea, chocolate, soft drinks, energy drinks, and other products.
Learn more about caffeine. Caffeine is naturally found in drinks like coffee and tea and food like chocolate. It’s a stimulant, so it’s often used to help people feel more awake or refreshed.