Kanna

Kanna, the common name for Sceletium tortuosum, is a succulent plant native to the Cape region of South Africa. It has long been used by indigenous Khoisan peoples and is now sold worldwide as a herbal product, typically as dried plant material, powder, extract, or capsule.

Chemically, kanna contains several alkaloids, including mesembrenine, mesembrenol, mesembrine, and tortuosamine, which interact with the brain's serotonin system. Mesembrine is known as a serotonin reuptake inhibitor, and the extracts are reported to produce mood-elevating and anxiolytic effects in traditional and contemporary use, though research is limited and findings are not conclusive.

Traditionally, kanna has been chewed, snuffed, or smoked to curb fatigue, suppress hunger and thirst, and promote sociability and mood. It was used in ceremonies and everyday social contexts by Khoikhoi and San communities.

Modern use and regulation: In many countries kanna is marketed as a dietary supplement or herbal remedy for mood, anxiety, and stress. It is not approved as a medicine by major regulatory agencies; regulation varies by country and products may be subject to separate drug or supplement rules. Consumers should exercise caution.

Safety and interactions: Kanna can interact with antidepressants, particularly selective serotonin reuptake inhibitors and monoamine oxidase inhibitors, raising the risk of serotonin syndrome. Side effects may include headaches, nausea, and dizziness; high doses can cause sedation or dissociation. There are rare reports of liver injury associated with kanna use. It should be avoided in pregnancy and with severe liver disease or concurrent psychiatric illness, and not combined with other serotonergic drugs.

Ecology and cultivation: Sceletium tortuosum is a drought-tolerant perennial or short-lived shrub native to South Africa, often growing on rocky slopes and sandy soils. It is grown ornamentally and for medicinal use in warm climates.