Mesembryanthemum tortuosum

Mesembryanthemum tortuosum or Sceletium tortuosum, commonly known as kanna, channa, kougoed, or Namaqua skeletonfig, is a succulent plant in the family Aizoaceae, native to the Cape Provinces of South Africa. Traditionally, it has been fermented and chewed as kougoed—an Afrikaans term meaning ‘chewable thing’—by the indigenous Khoisan peoples for its psychoactive effects. The plant contains several active alkaloids, particularly mesembrine.

It has likely been used by South African pastoralists and hunter-gatherers for thousands of years. The first written account of its use dates to 1662, recorded by Jan van Riebeeck. The dried plant was traditionally chewed with the saliva swallowed. It has also been prepared in various forms, including gel caps, teas, tinctures, snuff, and smoked. In traditional medicine, it is primarily used to alleviate stress, depression, pain, and hunger. It is currently classified as a species of least concern, though wild populations face pressure from overharvesting.

Kanna has gained global attention for its stress-relieving and mood-enhancing properties, with modern research focusing on the potential of its bioactive alkaloids to support mental health. Preliminary studies using kanna extract Zembrin suggest it may have benefits for mood, anxiety, stress, sleep, and cognitive function. However, it showed no significant effect on reducing anxiety symptoms compared to placebo in a meta-analysis of randomized clinical trials. Clinical data are currently insufficient to support the use of kanna for any specific medical indication. Kanna shows potent inhibition of the serotonin transporter and PDE4. It promotes monoamine release through vesicular monoamine transporter-2 upregulation, with serotonin reuptake inhibition as a secondary action. It is used as a party drug for its euphoric effects.