Catha Edulis

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OFFICIAL NAMES: Catha edulis or Catha edulis Forssk

STREET NAMES: Khat, qat in Yemen, tschat in Ethiopia; miraa in Kenya; Abyssinian tea, African salad, African tea, Arabian tea, Bushman's tea, chafta, chat, ciat, crafta, djimma, flower of paradise, ikwa, ischott, iubulu, kaad, kafta, kat, la salade, liss, liruti, mairongi, mandoma, maonj, marongi, mbugula mabwe, mhulu, miungi, mlonge, msabukinga, masbukinja, msuruti, msuvuti, msekera, muholo, muhulu, muirungi, mulungi, muraa, musitate, mutsawari, mwandama, mzengo, nangungwe, ol meraa, ol nerra, quat, salahin, seri, Somali tea, tohai, tohat, tsad, tschad, tschat, tshut, tumayot, waifo, warfi, warfo

DRUG CLASSIFICATIONS: Cathinone: Schedule I, stimulant; cathine: Schedule IV, stimulant


The Catha edulis (khat) plant is a flowering evergreen shrub or tree with a slender trunk and thin bark. Khat is a central nervous system (CNS) stimulant that contains the psychoactive ingredients cathinone, which is structurally and chemically similar to the d-amphetamines (drugs like cocaine); and cathine, a milder form of cathinone; as well as cahine and norephedrine. Khat, which is believed to have originated in Ethiopia, is native to the eastern and southern regions of Africa and the southern Arab peninsula. However, the plant was later cultivated in Kenya, Malawi (formerly Nyasaland), Uganda, Tanzania (formerly Tanganyika), Arabia, Zimbabwe (formerly the Congo), Zambia (formerly Rhodesia), and South Africa. In those countries, khat trees are sometimes planted between coffee trees.

The plant grows best at elevations of 4,500–6,500 ft (1,370–1,980 m). In areas with frost, the shrub grows no higher than 5 ft (1.5 m). However, in areas where the rainfall is heavy, such as the highlands of Ethiopia and regions near the equator, khat trees can reach 20 ft (6 m). Although khat thrives in areas of plentiful rainfall, the plant also grows during periods of drought when other crops fail.

Khat's elliptical leaves, which resemble basil in size and shape, are reddish-green and glossy but become yellow-green and leathery as they age. The plant's flowers are small and white. The most prized parts of the plants are the young shoots, buds, and leaves near the top of the plant. Although the older leaves near the middle and lower sections of the plant are also used, as are the stems, these portions of the plant are considered inferior and less potent.

The leaves are not picked until the plant is four years old; harvest occurs during the dry season. The first harvest is considered inferior to later ones. Leaves gathered from plants over six years of age are most valued, possibly due to greater alkaloid accumulation. In addition, the foliage of cultivated plants is preferred over wild plants.

The production and consumption of khat occupy a prominent position in Yemeni culture. The increased affluence of that country in the 1980s and 1990s allowed an increasing percentage of the population to indulge in the habit, which the government has attempted through various measures to discourage. Greater demand, however, has fueled a substantial increase in khat acreage. As productivity declines, older coffee plantations are often converted to khat fields. Much of the land devoted to khat was formerly considered marginal for commercial agricultural purposes and later benefited from regular soil-enhancement programs. A portion of Yemen's khat crop is exported to Ethiopia and Kenya.

Stimulant properties

Khat leaves left unrefrigerated beyond 48 hours contain only cathine, which explains users' preference for fresh leaves. The young leaves and buds are chewed as a mild stimulant; the chewing produces a strong aroma and generates intense thirst.

The amphetamine class of stimulants are potent, indirect-acting agents that cause a release of the neurotransmitters dopamine and norepinephrine from storage areas in the CNS. The mildest CNS stimulant is phenethylamine (PEA), a component of cheese and chocolate, while cocaine is considered a potent CNS stimulant.

The neurons activated by amphetamines are dense in the pleasure center of the brain; and the depletion of the stores sets up a demand for progressively higher doses to achieve the same "high," and accounts for the sometimes profound depression, or "crash," that follows a drug binge.

In experiments with such animals as rats and monkeys, which were trained to self-administer amphetamines, researchers observed a pattern that they described as "spree-type." The animals took the drug frequently day and night, stopping only after becoming exhausted, and beginning again after recovery. This pattern is similar to that seen in amphetamine-dependent humans. Thus, in terms of pharmacology, chewing khat leaves produces the same amphetamine effect.

Stimulants first may cause exhilaration and hyperactivity, dilated pupils, then produce irritability, anxiety, apprehension, and insomnia. Large doses of stimulants can cause repetitive teeth grinding, weight loss, and paranoia. An overdose can result in dizziness, tremors, agitation, panic, hostility, abdominal cramps, chest pains, and palpitations. Extreme overdoses can result in cardiac arrest, stroke, or death.

In the 1990s, methcathinone—called by various street names such as cat, goob, Jeff, speed, bathtub speed, mulka, gaggers, the C, wild cat, Cadillac express, and ephedrine—appeared as a drug of abuse on the black market. Methcathinone, a synthetic form of cathinone, is an even more potent stimulant than its natural counterpart and is illegal in the United States.

Although methcathinone was studied in the 1950s to determine its potential for medical use, the study was abandoned due to the safety risks and side effects. Then in 1989, a University of Michigan student stole the old drug samples and documentation and began to manufacture and sell the drug throughout the United States.

Traditional use

The ancient Egyptians considered khat to be a sacred plant, a "divine food." The Egyptians did not use khat merely for its stimulant properties but rather to unlock what they considered to be the divine aspect of their human nature.

Khat is believed to have been traded as a commodity even before coffee and is used throughout the Middle East countries in much the same way as coffee is used in Western culture. In addition to its use as a mild stimulant, khat use in Africa and the Middle East is more of a social phenomenon. Its intake occurs in moderation, for the most part, and often takes place in special rooms designed for that purpose.

Since antiquity, khat has also been used in religious contexts by natives of Eastern Africa and the Arab peninsula. For example, khat was used, in moderation, as a stimulant to alleviate feelings of hunger (some members of the Islamic faith use khat during Ramadan, the ninth month of the Moslem year, which is spent fasting from sunrise to sunset) and fatigue.

In Yemen, khat has played a pivotal role in poetry, music, architecture, family relations, wedding and funerary rites, home furnishings, clothes, what people eat, when restaurants open and close, where roads go to and where not, who owns a car and who does not, office hours, television schedules, and even sexual relations. However, there has been a decreased productivity and a diversion of income attributed to its use as well.

Modern use

Conservative estimates state that khat accounts for one third of the gross national product of Yemen. In Ethiopia, khat is also a major cash crop. In the United States, khat use is most popular among immigrants from Yemen and the East African nations of Somalia and Ethiopia. The U.S. public became more aware of this exotic drug through media reports pertaining to the United Nations' mission in Somalia, where khat use is endemic, and the drug's role in the Persian Gulf War.

Khat can be purchased in the United States in various ethnic bars, restaurants, grocery stores, and smoke shops. Once imported and available on the streets of the United States, khat found its way into the hands of a broader population of users than ever before. Its use has been linked to the dance/rave scene in the United States as well as in countries around the world.

Fresh khat leaves are most often prepared for shipment in bouquet-sized bundles, wrapped in plastic bags or banana leaves, then tied together. The bundles are sprayed with water to keep the leaves fresh and moist, especially important when the leaves are shipped outside of the country of origin.


Although the Catha edulis plant contains a number of chemicals, vitamins, and minerals, its main active ingredient is cathinone, an alkaloid with a chemical structure similar to ephedrine and d-amphetamine. Like amphetamine, it increases the levels of dopamine in the brain and acts as a mild stimulant. For this reason, khat is sometimes referred to as a natural amphetamine.

Within two days of harvest, cathonine levels in the plant's leaves diminish, and the substance that remains is a milder form of cathonine called cathine.


Khat leaves are typically chewed like tobacco. Users fill the mouth with fresh leaves that they chew to release the active ingredients. Khat is also sold as dried or crushed leaves, frozen leaves, or in powdered form.

Another method of ingesting khat is by chewing a paste made of khat leaves, water, and sugar or honey, sometimes flavored with herbs. A tea made from the flowers of the khat plant—"flower of paradise" in Yemen—is considered restorative. In addition, the leaves are sometimes added to plain tea, or smoked in combination with tobacco. Ethiopians often drink a juice extract made from khat leaves.


In the United States, khat is not approved for medical use. However, a study in the January 2000 issue of Journal of Pharmacy and Pharmacology concluded that khat, like amphetamines and ibuprofen, can relieve pain.

Although it is mainly used in social situations throughout Africa and the Middle East, khat is sometimes used by farmers and laborers to alleviate fatigue, by students to improve concentration before exams, and by the elderly to improve cognitive function. In Ethiopia, khat advocates claim that the plant eases symptoms of diabetes, asthma, and intestinal tract disorders. The processed leaves and roots are used to treat influenza, cough, other respiratory ailments, and gonorrhea.

Amphetamines were first marketed in the United States in 1932 as a treatment for asthma, and subsequently were used to treat narcolepsy. Gaining popularity as a defense against battle fatigue in World War II, nearly 200 million amphetamine tablets were issued to American soldiers stationed in Great Britain during the war. By the 1950s, stimulants were used to treat depression. But often amphetamines were used by people who just needed a lift, or who needed to stay alert, such as workers on the night shift, students, and truck drivers. However, by 1970, the Controlled Substances Act (CSA) severely restricted the use of amphetamines, which were classified as Schedule II drugs.

As of 2001, the U.S. Food and Drug Administration (FDA) approved the use of stimulants for treating attention-deficit/hyperactivity disorder (ADHD), narcolepsy, and Parkinson's disease. These drugs are also used in combination with other medications to manage pain, and to treat depression and other psychiatric disorders.

Because amphetamines are anorectics (appetite suppressants), these drugs were formerly the treatment of choice for obesity. Due to the potential for abuse and for adverse side effects such as increased heart and respiratory rate, and increased blood pressure, these drugs

were eventually replaced by safer weight-loss medications. However, khat, an amphetamine-like substance, is used to counter obesity in countries such as Germany.

The amphetamines were replaced by amphetamine analogs—substances somewhat less potent than amphetamines. Fen-Phen, the combination of fenfluramine and phentermine, was a popular appetite suppressant in the 1990s, but was associated with severe health problems such as pulmonary hypertension, heart valve dysfunction, and nerve damage. As a result, both drugs were withdrawn from the market.

Sibutramine (Meridia), a weight-loss drug introduced in 1998, inhibits the reuptake of the brain chemicals norepinephrine, dopamine, and serotonin, but does not promote monoamine release like the amphetamines. Yet the drug has been linked to serious side effects, including rapid heart rate, increased blood pressure, heart disease, stroke, seizure, and mental impairments. In March 2002, Italy's Health Ministry announced that it was immediately withdrawing all sibutramine products from the market due to health-related problems. Also, Meridia was the subject of a class action lawsuit filed in the United States.


For centuries, khat use was long confined to its native growing regions because the leaves needed to reach their destination within 48 hours of harvesting to retain their potency. However, with improved roads and air transportation, khat use spread to many other parts of the globe. During the 1980s, a flood of refugees from sub-Saharan Africa entered the United States, Canada, Australia, and various West European countries, bringing their habit of khat chewing with them.

Scope and severity

Worldwide, it is estimated that from five to 10 million people use khat on a daily basis. Many of the users originate from countries between Sudan and Madagascar and in the southwestern part of the Arab peninsula, especially Yemen.

In Yemen, khat use is so widespread (about 80% of the adult population) that even government officials use the drug openly. Also, visitors are encouraged to try it. However, in 1999, concerned that too many khat-chewing government workers were neglecting their jobs and whiling away their income, President Ali Abdullah Saleh attempted to set an example by announcing that he would limit his chewing to weekends.

Although statistics vary from country to country, estimates suggest that khat users spend from $6 to $20 per day on their habit. Growing and selling khat is also big business. The Yemeni production and distribution of khat traded to Somalia alone brings in an estimated $100 million annually. Khat must be imported because the Somalis only produce enough khat for local use. Within Somalia, 61% of the population use khat, with 18% reporting habitual use and 21% occasional use. Somalian warlords have been known to ration it out to soldiers on a daily basis. And in Djibouti, the United Nations estimates that approximately 98% of the men use khat, which is flown in from Ethiopia.

Khat use has also spread into Europe. In the United Kingdom (where khat is legal), it is occasionally imported in twig-like bunches for sale in some grocery stores and specialty health food stores.

Since the 1990s, news reports and statistics suggest that the U.S. market for khat, although more limited than other illegal drugs, has increased. Khat is smuggled into the United States and commonly sold in restaurants, bars, grocery stores, and smoke shops that cater to East Africans and Yemeni immigrants. It is also bought and sold by soldiers who encountered it during foreign service.

In 2000, U.S. Customs seized 70,008 lbs (31,755 kg) of khat on its way from East Africa and Yemen, up from 48,938 lbs (22,197 kg) in 1999. Marijuana seizures, by comparison, totaled 1.2 million lbs (544,310 kg) in 2000.

Age, ethnic, and gender trends

Traditionally, the bitter leaf of the khat plant was chewed primarily in social situations by older men in Yemen and throughout Saharan and sub-Saharan Africa. However, in the early 1990s, a growing number of men began chewing khat for up to 12 hours a day. The reasons for this increase in khat use has been attributed to feelings of hopelessness and boredom in the face of rising poverty and joblessness in many Middle Eastern and African countries.

Khat use also began spreading to an even greater number of women and children. In 2000, it was reported that 80% of Yemeni males, 60% of females, and an increasing number of children under the age of 10 had chewed khat daily for long periods of their life.

In Saudi Arabia, although the cultivation and consumption of khat are forbidden, and the ban is strictly enforced, khat chewing continues. Furthermore, the ban on khat is also supported by the Saudi clergy on the grounds that the Koran forbids anything that harms the body. However, this perspective on khat is not maintained by the Yemeni religious authorities.

During the 1990s, khat was introduced on college campuses in the United States and elsewhere, and a growing number of students began using the stimulant to stay up later at night. Khat was labeled the "poor man's ecstasy."


Although the main effects of chewing khat are a moderate degree of euphoria and excitation, users also report increased levels of:

  • concentration
  • loquaciousness
  • confidence
  • friendliness
  • contentment

High doses or prolonged use, however, may induce sleeplessness, hyperactivity, and aggression. In addition, according to the Drug Enforcement Administration (DEA), compulsive use "may result in manic behavior with grandiose delusions or in a paranoid-type of illness, sometimes accompanied by hallucinations." Although psychosis has been reported, the phenomenon is rare. Khat has also been known to cause cognitive impairment.

International organizations have been confronting problems associated with khat since 1935. The World Health Organization (WHO) played a pivotal role in encouraging and funding scientific studies designed to understand not only khat's active ingredients but also the physical, psychological, and social problems associated with its use. In 1980, the WHO classified khat as a drug of abuse that may produce mild to moderate psychological dependency.


In one study on a group of 80 healthy volunteers, researchers found that during a three-hour period of chewing fresh khat leaves, there was a significant progressive rise in blood pressure and heart rate even one hour after chewing had ceased. These reactions were due to the stimulant effects of the drug.

Additional physiologic effects reported with khat use include:

  • dizziness
  • lassitude
  • stomach pain
  • thirst
  • dilated pupils (mydriasis)
  • anorexia
  • constipation
  • impotence
  • insomnia
  • thirst

The unpleasant side effects of khat, especially the insomnia, have led some users to seek counteracting agents such as tranquilizers and alcohol—substances that are particularly hazardous in combination with khat.

Harmful side effects

In one study, 44 species of fungus were isolated from 30 samples of khat leaves gathered in Yemen. Researchers considered the toxins found in some of these species a threat to public health.

In addition, to ward off a wide range of insects, diseases, and weeds—and to preserve an important cash crop—toxic chemicals are often used to spray the plants. When the leaves are chewed, these toxins enter the bloodstream, causing potential health problems, including chemical hepatitis.

The overall effect of khat on patients with diabetes is harmful. The anorectic effect of khat leads to skipping meals; also, users are less likely to follow dietary advice, and consuming sweet beverages with khat aggravates hyperglycemia (high blood sugar levels). The anorectic nature of khat largely explains the malnutrition often seen in habitual khat users.

Some researchers believe that there is not a high potential for khat abuse because the volume of leaves required limits the ingestion and absorption of a large amount of the active ingredients. Yet the effects of khat have been difficult to quantify. The leaves are a nonstandardized material, and their potency depends on freshness and place of origin. Yet although there is no known record of khat resulting in overdose, adverse side effects are somewhat greater in children, in those over 55 years of age, and in those who use large quantities of the substance for extended periods of time.

Long-term health effects

Because khat is chewed for the most part, medical problems associated with the oral cavity and digestive tract are common and may lead to inflammation and secondary infections. There is also some evidence of increased risk of oral cancer.

In a 1995 study published by the British Journal of Urology, researchers found that khat chewing inhibits urine flow, an effect caused by blood vessel constriction, which also causes erectile dysfunction. This constriction also affects blood pressure and heart rate; however, further studies are needed to determine the possible long-term cardiovascular damage associated with regular khat use.

Several studies suggest that long-term khat use causes reproductive toxicity. In addition to neurological effects—damage to the nervous and respiratory system have been documented—khat consumption is also associated with reproductive problems in men and women. Heavy use of khat is associated with decreased semen volume, sperm count, and sperm motility, and with an increased number of sperm appearing microscopically abnormal.

Women who chewed khat gained less weight during their pregnancies, and blood flow to the uterus was decreased, retarding fetal development and resulting in low-birth weight babies with a greater potential for medical problems. Mothers also produced less milk. These adverse effects are considered a serous public health concern by some researchers.


Khat may interact with drugs used in treatment of other diseases and produce emotional and mental disorders. For example, when combined with niridazole—a drug used in treating schistosomiasis (a parasitic disease endemic throughout Asia, Africa, and tropical America)—severe anxiety reactions, insomnia, and even psychoses may develop. Also, khat would be likely to react with other stimulants such as alcohol, coffee, or cigarettes, causing palpitations and agitation.

Similarly, in a study published in the May 2001 issue of International Journal of Cancer, researchers found that khat chewing, especially when accompanied by alcohol and tobacco consumption, may cause oral malignancy.

Monoamine oxidase inhibitors (used in the treatment of bipolar disorder) should not be used with khat, as the combination may cause a potentially dangerous increase in blood pressure.


Because the psychiatric manifestations induced by khat are similar to the effects of other known stimulants, treatment of khat dependency is similar to that of dependency on amphetamines.

Reportedly, there are no physical symptoms of khat withdrawal of the type associated with other stimulants such as alcohol, morphine, or the barbiturates. Abandoning the habit, however, is frequently followed by depression, loss of energy, and an increased desire to sleep. The severity of depression varies and may lead to agitation and sometimes sleep disturbances. For the most part, former users are less prone to constipation and smoke less. If they consume alcohol, they usually drink less, and their appetite increases.

In a study published in the July 1995 issue of American Journal of Therapy, researchers described a successful attempt to treat a case of khat dependency using protocols similar to those developed for cocaine. Specific procedures for treatment entailed an outpatient detoxification with bromocriptine mesylate 1.25 mg every six hours. The dosage was gradually tapered downward over four weeks. Previous attempts to treat khat-induced psychosis have employed thioridazine (300 mg a day) for one week without symptom recurrence.


Although immediate and severe medical problems are thought to be infrequent, khat use often leads to health problems. Reducing khat consumption, according to researchers, would relieve several million people, mostly men, of a costly and potentially addictive habit. It would also make available scarce arable land and irrigation water for other crops. Government figures show that khat consumes 75% of Yemen's irrigation capabilities.

Khat chewers may cause harm to their families due to negligence, dissipation of the family income, and inappropriate behavior. In Yemen, even poor families admit to spending at least 50% of their income on khat.

Overall, women and children seem to be suffering most from khat consumption. Many men spend so much money on khat that their families go hungry and remain in poverty. Several countries concerned by the khat problem, such as Yemen, have taken steps to restrict its use.


Cathinone and cathine are controlled under the United Nations' Convention on Psychotropic Substances. In the United States, Canada, Switzerland, Scandinavia, and most of the Middle East, excluding Yemen, the leaf itself is banned. The khat plant is not controlled under domestic law in the United Kingdom.

From the standpoint of their cultural norms, however, African/Arab sellers and users living outside of their country of origin do not consider khat to be illegal and often openly advertise its availability on signs in restaurants and grocery stores much as they would any other food product.

Legal history

Khat was freely available in Saudi Arabia prior to 1971, when it was classified as a narcotic and declared illegal. Further cultivation, commercial activity, and personal khat use was banned. The basis for this legal change was the local religious teaching of Islam, which strongly recommends preventing harm to the individual or society. The Saudi government applied very severe punishments against users and smugglers, including the death penalty. However, in some areas bordering Yemen, many have continued to use khat.

Khat leaves have been illicitly bundled and shipped into the United States in increasing amounts since the 1990s. According to the Federal Drug Information Network database, more than 57,000 lbs (25,850 kg) of khat leaves were seized in 1998.

Nevertheless, law enforcement efforts directed against khat use in the United States have been minimal as there is some doubt about whether khat will ever become as popular a street drug as marijuana, crack cocaine, and other drugs. However, illegal laboratories have been discovered manufacturing a synthetic form or khat's most active ingredient (cathinone), which is called "methcathinone" and known on the street as "cat."

Federal guidelines, regulations, and penalties

In the United States, the Federal Controlled Substances Act (CSA), Title II of the Comprehensive Drug Abuse Prevention and Control Act of 1970, consolidates a number of laws regulating the manufacture and distribution of drugs and chemicals used in the illegal production of controlled substances.

The CSA classifies cathinone is a Schedule I substance, the same category as heroin and cocaine, and cathine as Schedule IV, which carries no mandatory prison penalties.

Federal trafficking penalties for Schedule I and II drugs range from a minimum of five years to a maximum of life in prison. Penalties for trafficking Schedule III and IV drugs range from three to five years in prison and a fine of $25,000. However, in the case of khat, drug enforcement in the United States appears to be random and not a high priority.

Until the late 1990s, authorities had been foregoing prosecutions of khat smugglers. According to officials, khat presents some unusual problems for prosecutors, particularly the short shelf-life of the drug. In addition, because of the bulk of the product, the amount carried by a single person is under the level to trigger federal prosecution. As a result, most air shipments are merely seized and shipped to government incinerators for destruction, while the couriers are deported.

See also Amphetamines; Ecstasy; Ephedra; Herbal drugs; Methamphetamines



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Keltner, Norman L., and David G. Folks. Psychotropic Drugs. Philadelphia: Mosby, 2001.

Rushby, Kevin. Eating the Flowers of Paradise: A Journey Through the Drug Fields of Ethiopia and Yemen. New York: St. Martin's Press, 1999.


Bures, Frank. "From Civil War to Drug War." (November/December 2001).

Kandela, P. "Women's Rights, a Tourist Boom, and the Power of Khat in Yemen." Lancet (April 22, 2000): 1437.

Robinson, Simon. "The Cost of Catha Edulis." Time Europe (December 20, 1999).


National Clearinghouse for Alcohol and Drug Information (NCADI), P.O. Box 2345, Rockville, MD, USA, 20847-2345,(800) 729-6686, [email protected], <>.

National Council on Alcohol and Drug Depenedence, 12 West 21st Street, New York, NY, USA, 10010, (800) 622-2255 or (800) 475-4673, <>.

National Institute on Drug Abuse (NIDA), National Institutes of Health, 6001 Executive Boulevard, Room 5213, Bethesda, MD, USA, 20892-9561, (301) 443-1124, (888) 644-6432, [email protected], <>.

Substance Abuse and Mental Health Services Administration (SAMSHA)/Center for Substance Abuse Treatment (CSAT), 5600 Fishers Lane, Rockville, MD, USA, 20857, (301) 443-8956, [email protected], <>.

Genevieve T. Slomski, Ph.D.