Khat contains the alkaloid called cathinone, an amphetamine-like stimulant which is said to cause excitement, loss of appetite and euphoria. In 1980 the World Health Organization classified khat as a drug of abuse that can produce mild to moderate psychological dependence.

It is a controlled/illegal substance in many countries. Khat is a slow-growing shrub or tree that grows to between 1.5 metres and 20 metres tall, depending on region and rainfall, with evergreen leaves 5–10cm long and 1–4cm broad. The flowers are produced on short axillary cymes 4–8cm long, each flower small, with five white petals. The fruit is an oblong three-valved capsule containing 1–3 seeds.

hat use has traditionally been confined to the regions where khat is grown, because only the fresh leaves have the desired stimulating effects. In recent years improved roads, off-road motor vehicles and air transport have increased the global distribution of this perishable commodity. Traditionally, khat has been used as a socializing drug.

It takes nearly seven to eight years for the Khat plant to reach its full height. Khat requires a little maintenance as it needs a little more than sun and water. Ground water is often pumped from deep wells by diesel engines to irrigate the crops, or brought in by water trucks. The plants are watered heavily starting around a month before it is harvested to make the leaves and stems soft and moist. A good Khat plant can be harvested four times a year, providing a year long source of income for the farmer.

Khat consumption induces mild euphoria and excitement. Individuals become very talkative under the influence of the drug and may appear to be unrealistic and emotionally unstable. Khat can induce manic behaviors and hyperactivity. Khat is an effective anorectic and its use also results in constipation. Dilated pupils (mydriasis), which are prominent during khat consumption, reflect the sympathomimetic effects of the drug, which are also reflected in increased heart rate and blood pressure. A state of drowsy hallucinations (hypnagogic hallucinations) may result coming down from khat use as well. Withdrawal symptoms that may follow occasional use include mild depression and irritability. Withdrawal symptoms that may follow prolonged khat use include lethargy, mild depression, nightmares, and slight tremor.

Long-term use can precipitate the following effects: negative impact on liver function, permanent tooth darkening (of a greenish tinge), susceptibility to ulcers, and diminished sex drive. Those who abuse the drug generally cannot stay without it for more than 4–5 days, feeling tired and having difficulty concentrating.[15] Occasionally a psychosis can result, resembling a hypomanic state in presentation.

It is estimated that several million people are frequent users of khat.