Full profile

Also known asKanna, Zembrin
Best forMood support (preliminary) · Cognitive flexibility (preliminary)
Evidence gradeEmerging — Emerging — mostly preclinical or preliminary human data
Studied dose range25 mg/day of standardized extract (Zembrin).
Time to effectSome acute effects reported; trials commonly run several weeks.
Best formZembrin, the standardized branded extract used in available trials.

Evidence, honestly graded

Human trials of the Zembrin extract are small and sponsor-linked, with limited independent replication. Directionally interesting for mood and cognitive flexibility, but not yet a trial base to build a confident claim on.

See the full grading rubric — study type, replication, population match, and dose adequacy — in The Evidence Standard.

Side effects

  • Generally well tolerated in available trials

Who should avoid it or check first

  • On SSRIs or MAOIs without clinician guidance (see interaction caution)
  • Pregnant or breastfeeding without clinician guidance

Interactions

  • Avoid combining with SSRIs, other serotonergic medications, or MAOIs — theoretical serotonergic interaction risk — discuss with a clinician

Use caution stacking with

  • SSRIs, other serotonergic supplements, or MAOIs

What to look for on a label

  • Carry a clear interaction caution for SSRI/MAOI medication given the serotonergic mechanism under study.

References

  • Zembrin (Sceletium tortuosum) small human RCTs. Small, sponsor-linked double-blind trials report mood and cognitive-flexibility effects. Limited independent replication. Educational, not a product claim.

Primary citations for some entries above are still being compiled; those without a linked identifier are editorial summaries of the wider literature.

Grades and studied doses are our conservative reading of the human research, shown for education. They are not product claims, and a studied dose is not a recommended dose.

See how Sceletium Tortuosum compares on grade, dose, and goal in the Evidence Explorer.