Khat

Khat is a stimulant obtained from the leaves and stems of the Catha edulis shrub, native to East Africa and the Arabian Peninsula.1 Its usage can be traced back to ancient times and is deeply ingrained in the social and cultural norms of countries such as Yemen, Ethiopia, and Somalia. Traditionally, khat leaves are chewed in these regions to induce stimulant effects during social and religious gatherings.2 The practice has now extended to other parts of the world, including Europe and North America, often within immigrant communities.4

Khat contains active compounds known as cathinone and cathine, which are structurally similar to amphetamines and induce stimulant effects.¹  The immediate effects include heightened alertness, increased energy, and euphoria.²  However, excessive and prolonged use is associated with various health concerns.

While khat holds traditional and cultural importance in some societies, its pharmacological effects pose significant health and social challenges. Regulatory approaches differ by country, with some having completely banned its use due to its negative impacts.³

Appearance

Khat leaves are generally a vibrant green, resembling mint or basil leaves. The leaves are typically glossy and oval-shaped. Stems are also chewed and can vary in thickness. Freshness is often a prized characteristic, and the leaves may wilt and brown if they are not consumed soon after harvesting. ¹

Tastе

The taste of khat is often described as bitter and astringent, with some users reporting an initial unpleasant taste that may become more tolerable or enjoyable over time. The bitterness is attributed to its active compounds, cathinone and cathine.²

Smell

Fresh khat leaves have a slightly aromatic, herbal smell. The scent is not overwhelmingly strong but can be described as fresh and green, similar to freshly cut grass or herbs.⁴

In summary, khat’s physical characteristics — its vibrant green appearance, bitter taste, and herbal aroma — are distinctive features that its users recognise. These traits are important for cultural reasons and for identifying the plant’s freshness, a key factor in its potency.¹

• Minimum to feel something (mg): The minimum active dose of cathinone, the primary psychoactive component of khat, is not well-established in the scientific literature. However, reports suggest that chewing just a few leaves may produce an effect.¹
• Low dose: A low dose generally consists of chewing a small bundle of leaves for a short period, although the exact milligram dosage is not well-documented.
• Common dose: A common dose usually involves chewing a moderate amount of leaves over an extended period, often several hours, to maintain the stimulant effect.
• High dose: A high dose could involve chewing large amounts of the plant material for an extended period, which might lead to more severe side effects such as hypertension and increased heart rate.¹

It’s essential to note that the potency of khat can vary depending on factors like the freshness of the leaves and the specific strain of the plant. Therefore, the actual dose of active compounds ingested can vary widely among users.

Exceeding High Dose:
When users exceed a high dose of khat, severe health complications can arise. These may include acute cardiovascular problems like elevated heart rate and blood pressure, as well as severe anxiety, insomnia, and even psychosis.^{3 ; 5}  

When consuming khat, individuals often report increased alertness, heightened energy, and euphoria. These effects are usually followed by a “comedown” phase, characterised by irritability, insomnia, and lethargy.²

Users generally start to feel the effects of khat within 30 minutes to an hour after beginning to chew the leaves. The onset can be influenced by the potency of the leaves and individual metabolic rates.¹

The effects of Khat can last several hours, depending on the dosage and individual metabolism.

• Cardiovascular Risks: Khat use can increase heart rate and elevated blood pressure.
• Mental Health: It poses a risk to mental health, including increased anxiety, depression, and, in extreme cases, psychosis.
• Overdose: Overdose is less commonly reported compared to other stimulants. However, excessive use can result in extreme paranoia and hallucinations.³

Amphetamines can be highly addictive. Regular use can lead to physical dependence and withdrawal symptoms upon cessation. They can also lead to problematic use characterised by increased tolerance, meaning that higher doses are required to achieve the same effects and intense cravings for the drug. ¹

In the United Kingdom, khat is categorised as a Class C controlled substance under the Misuse of Drugs Act 1971. As of June 2014, the possession and distribution of khat are illegal. This means that being caught in possession could result in a prison term, whilst supply and production can incur even more severe penalties. ⁴

The interaction between khat and other substances has not been extensively researched. However, it is generally advised to avoid mixing khat with other psychoactive substances, particularly alcohol and stimulants. Such combinations can increase the risk of adverse cardiovascular events and exacerbate mental health issues like anxiety or depression. For instance, the simultaneous use of khat and alcohol can lead to increased intoxication and increased risk of liver toxicity. ³

1. Al-Motarreb, A., Baker, K., & Broadley, K. J. (2002). Khat: pharmacological and medical aspects and its social use in Yemen. Phytotherapy Research, 16(5), 403-413. https://onlinelibrary.wiley.com/doi/abs/10.1002/ptr.1106)
2. Hassan, N. A., Gunaid, A. A., Murray-Lyon, I. M. (2007). Khat (Catha edulis): Health aspects of khat chewing. Eastern Mediterranean Health Journal, 13(3), 706-718. https://applications.emro.who.int/emhj/1303/13_3_2007_706_718.pdf)
3. Corkery, J. M., Schifano, F., Oyefeso, A., Ghodse, A. H., Tonia, T., Naidoo, V., & Button, J. (2011). Overview of literature and information on “khat-related” mortality: A call for recognition of the issue and further research. Annali dell’Istituto Superiore di Sanità, 47(4), 445-464. https://www.scielosp.org/article/aiss/2011.v47n4/445-464/en/ )
4. European Monitoring Centre for Drugs and Drug Addiction. (n.d.). Khat Drug Profile. https://www.emcdda.europa.eu/publications/drug-profiles/khat_en )
5. National Institute on Drug Abuse (NIDA). (2007). Khat. Retrieved from the United States Department of Justice https://www.justice.gov/archive/ndic/pubs31/31482/index.htm)
6. Odenwald, M., Warfa, N., Bhui, K., & Elbert, T. (2010). The Stimulant Khat—Another Door in the Wall? A Call for Overcoming the Barriers. Journal of Ethnopharmacology, 132(3), 615–619. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3991038/)