For centuries, khat, the fresh young leaves of the Catha edulis shrub, have been consumed where the plant is cultivated, primarily in East Africa and the Arabian peninsula. There, chewing khat predates the use of coffee and is used in a similar social context. Chewed in moderation, khat alleviates fatigue and reduces appetite. Compulsive use may result in manic behavior with grandiose delusions or in a paranoid type of illness, sometimes accompanied by hallucinations.

Khat has been brought into the United States and other countries for use by emigrants from the source countries. It contains a number of chemicals among which are two controlled substances, cathinone (Schedule I) and cathine (Schedule IV). As the leaves mature or dry, cathinone is converted to cathine, which significantly reduces its stimulatory properties.