What is Kanna?

Kanna is a small ground-hugging plant from South Africa. Its Latin name is Sceletium tortuosum. People take it to lift mood, calm nerves and ease stress.

San and Khoikhoi people have used it for hundreds of years. They crushed the plant, let it ferment, then chewed it. The chewed form is called kougoed, which means "something to chew".

Today it is sold as capsules, powder, tea and drops. Most products are made from one plant only, with nothing else added.

The research is thin but not empty. A few small trials in healthy adults hint at mild effects on mood and stress. Long use in tradition is not proof that a plant works, and that holds true here.

How does Kanna work?

Kanna is thought to act on serotonin, a brain chemical linked to mood. Lab tests show its plant compounds slow the way brain cells mop serotonin back up. That would leave a little more of it active for a short time.

The same compounds also block an enzyme called PDE4. Blocking it may affect alertness and mood. This has been shown in lab dishes, not in people.

How much of this happens in a living human body is still unclear. Treat the story above as a good guess, not a settled fact.

What forms does Kanna come in?

Kanna comes in several forms:

Dried, fermented plant material for chewing. Loose powder. Capsules and tablets, often with a measured extract.

Tinctures and drops. Tea made from the dried plant. Snuff and chewing gum.

Some people sniff or smoke it. These routes are not studied and can irritate the nose, throat and lungs. Chewing, capsules and tea are the forms with the most human use behind them.

Where it comes from:

Kanna is one of the oldest known plant medicines of southern Africa. San and Khoikhoi people used it long before written records.

A Dutch record from 1662 describes local people trading and chewing it. They valued it for calm, for good mood, and for blunting hunger and thirst on long walks.

It remains a well-known folk remedy in South Africa today.

What does Kanna help with?

• Stress and feeling tense: This is the best-studied use, and the evidence is still small. In one placebo-controlled trial in healthy adults, a measured extract was taken for three months and was well tolerated. Any mood and stress effects reported were mild. No trial has tested kanna in people with a diagnosed stress or anxiety disorder.
• Low mood: Kanna has a long folk record as a mood lifter, but human proof is lacking. Its compounds act on serotonin in lab tests, the same chemical that many mood medicines act on. No trial has tested it in people with diagnosed depression. Do not swap a prescribed mood medicine for kanna.
• Anxious feelings: A small brain-scan study in healthy adults found less activity in the amygdala, the brain's alarm centre, after a single dose. That is a lab finding, not proof of relief in daily life. Tradition backs calm use; trials in anxious patients do not exist yet.
• Focus and mental sharpness: A small study in healthy older adults reported slight gains on some thinking tests. The group was small and the gains were modest. This is early work, and it has not been repeated widely.
• Hunger and thirst during long effort (traditional use): San and Khoikhoi hunters chewed kanna to blunt hunger and thirst on long walks. This use rests on tradition alone. No trial has measured it, and kanna is not a safe way to skip meals or water.

What are the side effects of Kanna?

• Headache
• Nausea or an upset stomach
• Loss of appetite
• Dry mouth
• Drowsiness or a foggy feeling
• Restlessness, jitters or irritability
• Trouble falling asleep if taken late in the day
• A mild rise in heart rate or blood pressure
• Nose or throat irritation if sniffed or smoked

Good to know:

Side effects are usually mild and pass when you stop. Headache and appetite loss are the ones people report most.

Serious harm is rare on its own. The real risk comes from mixing kanna with mood medicines, which is covered below.

How much Kanna should you take?

• Recommended daily: There is no official dose. The dose used most in research is 25 mg a day of a measured extract, taken as one capsule. Traditional chewing uses far more raw plant, often 100 mg to 1 g of powder. Raw powder strength varies a lot, so start at the low end. More is not better. High doses raise the chance of headache, nausea and a jittery feeling.
• Best time of day: Morning or early afternoon. Kanna can feel mildly stimulating, so a late dose may keep you awake.
• With or without food: Either works. Food may soften nausea, so take it with a meal if your stomach is sensitive.
• Time to effect: Most people notice something within 30 to 60 minutes of a dose. Any broader effect on mood or stress, if it comes, builds over days to weeks.
• How long to take it: Human trials have run up to three months at 25 mg a day. Nothing is known about longer use. Try it for two to four weeks, then judge honestly whether it helped. If it has not, stop rather than raise the dose.