Kanna + SSRIs
Kanna + SSRIs: the short answerKanna's main alkaloid (mesembrine) is itself a serotonin reuptake inhibitor — stacking it with a prescribed SSRI risks serotonin syndrome. This is a real interaction, not a theoretical one.
Why it’s dangerous
Mesembrine and related kanna alkaloids block the serotonin transporter, the same target as SSRIs. Combining the two can push serotonin signaling into the toxic range, and concentrated kanna extracts make the effective dose much harder to judge. The same caution applies to SNRIs, MAOIs, tramadol, MDMA, and St John's wort.
What happens
- Serotonin syndrome risk: agitation, sweating, tremor, diarrhea
- High temperature and muscle rigidity in severe cases
- Headache, nausea, and jitteriness at lower levels of excess serotonin
Warning signs
- Agitation, shivering, and sweating after combining the two
- Temperature above ~38.5°C/101°F with stiff or jerking muscles
- Racing heart or sudden confusion
What to do
- Call emergency services for fever, rigidity, or severe agitation
- Stop both and do not redose; keep cool and hydrated
- If you take any serotonergic medication, skip kanna and concentrated kanna extracts
- Tell your prescriber about herbal products you use — kanna included