Coffee

A native of the Kaffa province of Ethiopia, it was customarily drunk by warriors before going into battle, because it sharpened their mental performance, it made them more mentally active. This is the effect of caffeine, a psychoactive drug of moderate potency. It is an emergency drug for asthma attacks as it dilates bronchial passages.
Caution: It is generally addictive, may cause headaches, anxiety or panic, and certainly insomnia. It may worsen heartburn and depletes thiamin or vitamin B1. A major problem is the scores of chemicals used for the coffee bean's protection.