What Kind of Drug Is It?

Caffeine is a natural stimulant. A stimulant is a substance that increases the activity of a living organism or one of its parts. Caffeine was named after the shrubby coffee plant, which is native to the eastern African nation of Ethiopia. Although coffee is an ancient drink, it was not until 1821 that German chemist Friedlieb Ferdinand Runge finally isolated caffeine from the coffee bean.

Chemically speaking, caffeine is a bitter white ALKALOID. Its chemical formula is C₈H₁₀N₄O₂, and it is found especially in coffee and tea. Caffeine is considered both a drug and a psychoactive substance. Such substances alter the user's mental state or change behavior.

As a mild stimulant, it is often used medicinally to treat certain kinds of headache pain. Caffeine consumption speeds up the rate at which chemical reactions occur in the body. By increasing the...