What Does Kanna Feel Like?
No feeling is guaranteed. Here is what the studies measured, what people report, and why your experience may differ.
If you are wondering what kanna feels like, the honest answer is that it depends, and for some people it may be very little. Researchers have not run the kind of study that would let anyone promise a specific sensation. What exists is a handful of small trials that measured specific outcomes in healthy volunteers, plus traditional accounts and a lot of anecdote. This post sorts those apart.
No study has established a typical "kanna feeling." Small trials in healthy adults measured self-reported anxiety, reaction performance and brain responses, with mixed results, and mood scores did not change in at least one trial [2][3][5]. Effects vary by person, product and dose, are often subtle, and are not guaranteed.
What does kanna feel like, in short?
There is no established answer, because the research was not designed to describe sensations.
The published human work on kanna (Sceletium tortuosum) uses a single standardized extract, Zembrin, in small groups of healthy adults. Those trials counted things: scores on a computer task, heart rate, a rating scale, brain activity on a scanner. They did not ask people to write a diary of how the afternoon felt. So when someone tells you kanna feels like "a gentle mood lift" or "nothing much," that is a personal report, and the studies can neither confirm nor rule it out.
For the full study-by-study picture, see what the human studies on kanna show. Here we stay on one question: what could a person notice, and how sure can anyone be?
What did the studies actually measure?
Researchers measured brain responses, self-rated anxiety, reaction performance and safety markers, and the results were mixed.
| Study | Who and what dose | What was measured | What was found |
|---|---|---|---|
| Terburg 2013 [2] | 16 healthy adults, one 25 mg dose | Amygdala activity on fMRI while viewing faces | Reduced amygdala reactivity to fearful faces; this is a brain-scan result, not a reported feeling |
| Reay 2020 [3] | 20 healthy young volunteers across two studies, one 25 mg dose | Self-rated anxiety and heart rate around a stressor | Study 1 showed no treatment effect. Study 2 (simulated public speaking) showed lower self-rated anxiety before the stressor and a treatment-by-time interaction on heart rate |
| Chiu 2014 [4] | 21 healthy adults (mean age 54.6), 25 mg daily for 3 weeks | Cognitive tests, plus mood and sleep measures | Better cognitive set flexibility and executive function than placebo; the authors also reported positive changes in mood and sleep |
| Hoffman 2020 [5] | 60 recreationally trained adults, 25 mg daily for 8 days | Reaction task, mood score, alertness scale | Better performance on a complex reaction task under cognitive load; no change in mood or alertness scores |
| Nell 2013 [6] | 37 healthy adults, 8 mg or 25 mg daily for 3 months | Safety: vitals, ECG, bloodwork | No differences from placebo; efficacy was not assessed |
Two things stand out. First, only one of these studies (the second Reay study) showed lower self-rated anxiety, and the other Reay study did not. Second, the strongest signals were on tasks and scans, which a person would not necessarily notice from the inside. A faster reaction time of a fraction of a second is not something most people feel.
Context also matters. Several of these trials involve authors tied to the maker of Zembrin, the samples are small, and the volunteers were healthy [1][8]. A 2026 critical review called the evidence in animals and people "mixed" [8].
Why do people describe the effects as subtle?
Because in the trials, the measurable changes were modest and not consistent across outcomes.
The 8-day Hoffman trial is a good example. Participants performed better on one demanding task, yet their mood and alertness ratings did not move [5]. In Reay's two studies, one outcome shifted and the other study did not [3]. If a compound produced an obvious, dramatic state, you would expect clear, repeated signals on simple mood scales. That pattern is not what the trials report.
We would be careful not to over-read this. Absence of a signal in a small trial does not prove there is no effect for anyone, and the studies used specific doses of one extract. What it does support is a modest expectation. Anyone promising an unmistakable sensation is going beyond the published data.
It also helps to know the proposed mechanism, since it explains why researchers measured what they did. In lab work, a standardized extract blocked the serotonin transporter and inhibited PDE4, with mesembrine the most potent alkaloid at the transporter [9]. That is a laboratory finding. It does not tell you what a person will notice, and later cell work suggests the serotonin picture may be more complicated [1].
How was kanna described traditionally?
Traditional accounts describe use as a chewed or smoked plant, with uses recorded including mood elevation and suppressing thirst and hunger.
A 2021 review notes that kanna has a long history of traditional use as a masticatory and medicine by the San and Khoikhoi people, and that traditional uses included mood elevation and suppressing thirst and hunger [1]. Those are historical records of what people used it for, not clinical findings, and they involved whole plant material prepared in traditional ways, such as fermented "kougoed" [1]. A modern canned drink is a different product with a different dose. We cover the history in what is kanna.
What side effects have been reported?
The ones most often listed are headache and upset stomach.
WebMD names headache and upset stomach as common side effects of sceletium [7]. In the 3-month Nell trial, headache was the most common adverse event, and it was more frequent in the placebo group than in the kanna groups [6]. That trial found no differences in vitals, ECG or bloodwork, but it enrolled only 37 healthy adults and tested one extract [6].
The bigger safety questions are about medicines. WebMD flags possible concern with SSRIs, SNRIs, MAOIs, tricyclic antidepressants, antipsychotics, triptans and St. John's wort, says the interactions are not fully understood, and says it is not known how sceletium might affect pregnancy [7]. There is also not enough research to know how it interacts with alcohol [7], so we do not suggest combining them. More in is kanna safe.
Why would two people feel different things?
Several things differ from person to person and product to product, and the research cannot sort out which matters most.
- Dose and extract. The trials used 8 to 25 mg of Zembrin. Other extracts, and "alkaloid" milligram figures on other labels, are not interchangeable with that [1]. See kanna dosage.
- Product accuracy. NCCIH warns that "standardized" on a supplement label does not necessarily guarantee quality or consistency, and that what is on the label may not be what is in the product [10].
- Form. Drinks, capsules and tinctures may be absorbed differently, though we found no human study that compared them. See kanna drinks vs capsules.
- Expectation and setting. In placebo-controlled trials, people on placebo also report effects. That is one reason researchers use them, and why a personal anecdote is weak evidence.
- Other ingredients. Many drinks pair kanna with other botanicals, which makes it harder to know what you are noticing. See kanna and lion's mane.
Who should check with a doctor first?
Anyone taking antidepressants or other serotonergic medicines, anyone who is pregnant or nursing, and anyone with a medical condition.
The FDA advises talking to a health care professional before using a dietary supplement, and notes that some supplements can interact with medications [11]. Kanna is no exception. Because no one can predict what it will feel like for you, a low-key approach and a conversation with a clinician are more useful than chasing a particular sensation.
This page is general information, not medical advice. These statements have not been evaluated by the FDA. Kanna products are not intended for any disease or health condition.
References
- Olatunji TL, et al. Sceletium tortuosum: a review on its phytochemistry, pharmacokinetics, biological and clinical activities. J Ethnopharmacol 2021;280:114476. PubMed
- Terburg D, et al. Acute effects of Sceletium tortuosum (Zembrin), a dual 5-HT reuptake and PDE4 inhibitor, in the human amygdala and its connection to the hypothalamus. Neuropsychopharmacology 2013;38(13):2708-16. PubMed
- Reay J, et al. Sceletium tortuosum (Zembrin) ameliorates experimentally induced anxiety in healthy volunteers. Hum Psychopharmacol 2020;35(6):1-7. PubMed
- Chiu S, et al. Proof-of-concept randomized controlled study of cognition effects of the proprietary extract Sceletium tortuosum (Zembrin) targeting phosphodiesterase-4 in cognitively healthy subjects. Evid Based Complement Alternat Med 2014;2014:682014. PubMed
- Hoffman JR, et al. Ergogenic effects of 8 days of Sceletium tortuosum supplementation on mood, visual tracking, and reaction in recreationally trained men and women. J Strength Cond Res 2020;34(9):2476-81. PubMed
- Nell H, et al. A randomized, double-blind, parallel-group, placebo-controlled trial of Extract Sceletium tortuosum (Zembrin) in healthy adults. J Altern Complement Med 2013;19(11):898-904. PubMed
- WebMD. Sceletium: Uses, side effects, interactions. webmd.com
- de Jong M, et al. Mesembryanthemum tortuosum and Zembrin: mixed evidence from in vivo animal and clinical studies on their antidepressant and anxiolytic effects. Planta Med 2026;92(8):806-823. PubMed
- Harvey AL, et al. Pharmacological actions of the South African medicinal and functional food plant Sceletium tortuosum and its principal alkaloids. J Ethnopharmacol 2011;137(3):1124-9. PubMed
- National Center for Complementary and Integrative Health. Using dietary supplements wisely. nccih.nih.gov
- U.S. Food and Drug Administration. FDA 101: Dietary supplements. fda.gov
Frequently asked questions
What does kanna feel like?
There is no single answer. In small studies of healthy adults, researchers measured things like self-reported anxiety, reaction time and brain responses, with mixed results [2][3][5]. Individual experiences vary, are often subtle, and are not guaranteed.
How long does kanna take to work?
We found no published human study that measured when effects begin after a drink or capsule. Brands state their own estimates, but those are marketing claims, not study findings. See kanna drinks vs capsules.
Is kanna a stimulant or a sedative?
The studies we reviewed did not classify it either way. Lab work proposes that kanna alkaloids act on the serotonin transporter and PDE4 [9], which is a different mechanism from caffeine or from sedatives.
Can kanna cause side effects?
WebMD lists headache and upset stomach as common side effects of sceletium [7]. In a 3-month trial of 37 healthy adults, headache was the most common adverse event and was reported more often in the placebo group [6].
Will I feel anything at all?
Maybe not. In one 8-day study of 60 adults, mood and alertness scores did not change [5], and one of two anxiety studies showed no treatment effect [3].