Kanna (Sceletium tortuosum) has a reputation as a gentle herb, and for many people that's accurate. But gentle doesn't mean anything goes. Kanna's main compound works on the same system as many antidepressants, and that's exactly why some combinations can be dangerous. In this post you'll find which side effects are known, which combinations to never make, and who is better off skipping kanna.
Want to know what kanna is and where it comes from first? Read what is kanna.
How kanna works
Kanna is a succulent from South Africa. Its leaves contain a group of alkaloids, the best known being mesembrine, mesembrenone, mesembrenol and mesembranol. Mesembrine is the most potent and binds strongly to the serotonin transporter, so serotonin stays active between nerve cells for longer. The alkaloids also inhibit the enzyme PDE4, which raises levels of the signalling molecule cAMP.
That first action, serotonin reuptake inhibition, is exactly what SSRIs do. It's why interactions matter so much. Alkaloid content varies a lot between products: dried leaf contains far less than a concentrated extract such as Kanna Full Spectrum extract.
Known side effects
Reported side effects are usually mild and short-lived:
- headache
- mild nausea or an unsettled stomach
- temporary changes in appetite
- when snorted: irritation of the nasal lining
In placebo-controlled studies of a standardised kanna extract (8 and 25 mg a day, for up to three months), healthy adults had no more side effects than with placebo. Blood pressure, heart rate and blood values didn't change meaningfully. Keep two things in mind, though. That research covered one specific extract and only healthy people. And almost nothing is known about use beyond three months.
Combinations to avoid
This is the most important part of this post. Because kanna boosts serotonin activity, combining it with other serotonergic substances can lead to too much serotonin. That's called serotonin syndrome, and it can be serious.
| Combination | Why it's risky | Advice |
|---|---|---|
| Antidepressants (SSRIs, SNRIs) | Act on the same serotonin transporter | Never combine |
| MAO inhibitors, including ayahuasca, Banisteriopsis caapi and Peganum harmala (Syrian rue) | Block the breakdown of serotonin | Never combine |
| MDMA, tramadol, 5-HTP and St John's wort | Also raise serotonin | Never combine |
| Other psychiatric medication | Possible interaction with brain chemistry | Talk to your doctor first |
| PDE4 inhibitors such as roflumilast | Overlapping action | Talk to your doctor first |
| Alcohol and cannabis | May amplify each other's effects | Best not combined |
Recognise serotonin syndrome: agitation, sweating, fever, a fast heartbeat, shaking or twitching muscles and confusion. If you get these symptoms after a combination, call emergency services (112 in Europe, 911 in the US) or see a doctor straight away.
On antidepressants? Never stop taking them on your own to try kanna. Always talk to your doctor first.
Who should avoid kanna
- Anyone under 18.
- People taking antidepressants or other psychiatric medication.
- Pregnant or breastfeeding women: no safety research has been done.
- Anyone who still needs to drive or operate machinery.
Handling kanna sensibly
Avalon doesn't give usage advice, but a few general rules help keep risks low:
- Know what you have. An extract is much stronger than leaf, so never compare products one to one.
- Don't combine kanna with other substances, especially those in the table above.
- Don't drive or operate machinery after use.
- Unsure because of medication or your health? Ask your doctor or pharmacist first.
You'll find more background on Erowid and in our post on kanna's history and why people try it.
Is kanna legal?
In the Netherlands, kanna isn't covered by the Opium Act and is freely available. It isn't banned in most other European countries either. In the US it isn't controlled at federal level, but in Louisiana it may not be sold for human consumption. Always check the rules where you live. That responsibility is yours.
Frequently asked questions
Is kanna safe?
In studies of healthy adults, a standardised extract caused no more side effects than placebo. The biggest risk lies in combining it with other serotonergic substances, and little is known about long-term use.
Can I combine kanna with antidepressants?
No. Kanna acts on the same serotonin transporter as SSRIs and SNRIs. Together they can cause serotonin syndrome.
Can I use kanna after ayahuasca?
Don't combine kanna with ayahuasca or other MAO inhibitors, not on the same day and not shortly after one another.
Is kanna addictive?
There isn't enough research to give a firm answer. The available studies lasted three months at most.
Where can I find kanna?
You'll find kanna leaf and extracts in Avalon's kanna category. All products are for adults aged 18 and over only.
