Khat (Catha edulis Forsk) - And now there are three.

For centuries, a large number of people living in the southwestern part of the Arabian Peninsula and eastern Africa have chewed the fresh leaves and twigs of the plant Catha edulis Forsk, more commonly known as khat, for its psychostimulatory effect. The main active compound in khat is cathinone, whose synthetic derivatives form a part of the new psychoactive substances list. This review summaries the prevalence of khat use, its harvesting and consumption, the biosynthetic pathway in khat, the mechanism of action, the results from animal and human studies, and its dependence potential. It is unlikely that khat use will be prohibited in countries where it is traditionally consumed and socially acceptable unlike in other countries of the world where both the importation and the consumption of khat and cathinone is banned. Khat users being mainly Muslims prohibited from using alcohol or other drugs probably represent the largest global number of mono-drug users of an amphetamine-like stimulant. Thus, khat use represents a unique situation and a neglected area of research in Africa.