Caffeine

Caffeine is the most widely used psychoactive drug in the world. It exists naturally in plants and can also be produced synthetically and added to foods and beverages. Although frequently ingested through food (e.g., chocolate) and sometimes in pain, cold, or diet medication, caffeine is most often consumed through beverages such as coffee, tea, and carbonated soda or sodalike beverages (including many energy drinks). The amount of caffeine in coffee varies based on the size of the serving, the type of coffee, and how the coffee is prepared. According to the U.S. National Institute of Health, a 250-ml cup of coffee can vary in the quantity of contained caffeine from 5 mg in decaffeinated coffee to 30 mg to 120 mg in instant coffee and ...