Kanna and Lion's Mane: What Does the Research Show?
Two ingredients, two small bodies of research, and no study of the pair. A fair look at each.
If you have looked at the ingredient list on a few kanna drinks, you have probably noticed lion's mane next to it. The pairing is common enough that people ask whether the two belong together. This post covers kanna and lion's mane one at a time, using what small human studies measured, then looks at what is and is not known about taking them together.
Kanna and lion's mane each have a small body of human research, mostly short trials in healthy adults, with mixed results [1][2][3][6]. We found no human study that tested them together. Brands combine them because both are marketed as botanicals for focus and calm, not because a trial showed the combination does more than either alone.
Why are kanna and lion's mane in the same drink?
Because both are sold as botanical ingredients for the "calm and focus" part of the functional drink market.
Kanna (Sceletium tortuosum) is a South African succulent that the San and Khoikhoi people traditionally used as a masticatory (chewed) and medicine [7]. Lion's mane (Hericium erinaceus) is an edible mushroom sold as a supplement. Putting a calming-leaning ingredient and a focus-leaning ingredient in one can makes for a tidy story. That story is positioning. Whether the combination does anything different from either ingredient alone has not been tested in people, as far as we could find. For the broader context on how these products are marketed and regulated, see what functional beverages are.
What has research shown about kanna?
A few small, short trials in healthy adults, mostly using one extract, with mixed results.
In a 2013 study of 16 healthy adults, a single 25 mg dose of the Zembrin extract reduced amygdala reactivity to fearful faces on a brain scan [7]. In 2020, two studies in 20 healthy volunteers tested the same dose: one showed no treatment effect, and the other found lower self-rated anxiety before a simulated public-speaking task [8]. A 3-week trial of 25 mg daily in 21 healthy adults reported better cognitive set flexibility and executive function [9]. A 2026 review summed up the evidence as mixed, with small samples among the limitations [10]. We lay out the studies in what the human studies on kanna show, and several of them have authors tied to the extract's owner, which is worth keeping in mind [8][9][12].
What has research shown about lion's mane?
A handful of small human trials, with a positive signal in one older-adult study and null or mixed findings in healthy young adults.
We did not find a National Center for Complementary and Integrative Health page on lion's mane, so we relied on the published trials and a recent review.
- Mild cognitive impairment, 2009. In a double-blind, placebo-controlled trial, 30 Japanese adults aged 50 to 80 with mild cognitive impairment took about 3 g a day of lion's mane for 16 weeks. The lion's mane group scored significantly higher than placebo on a cognitive scale at weeks 8, 12 and 16. Four weeks after intake ended, scores had decreased significantly, and laboratory tests showed no adverse effect [1]. It was one small trial in a clinical population, not healthy people.
- Healthy adults, 2023. In a pilot trial of 41 healthy adults aged 18 to 45, 1.8 g daily for 28 days was tested. Participants were faster on the Stroop task an hour after a single dose, and there was a trend toward lower subjective stress after 28 days that did not reach significance. The authors reported null and limited negative findings as well and said the small sample calls for caution [2]. In the full paper, the lion's mane group recalled fewer correct words than placebo at some time points, and there was no effect on most other tasks [11].
- Healthy adults, 2025. In a crossover trial of 18 adults aged 18 to 35, a single 3 g dose of a 10:1 fruiting-body extract showed no significant effect on composite cognition or mood. One individual test, a pegboard task, was better at 90 minutes, and the authors said any benefits may be task or domain specific. Two authors work for a company that makes non-alcoholic drinks using lion's mane mushroom [3].
- Systematic review, 2025. A review of 26 studies found 5 randomized controlled trials, 3 pilot trials and 15 laboratory studies, with the remainder a cohort study, a case report and a computer analysis. Its authors list stomach discomfort, headache and allergic reactions as potential side effects, commonly unreported [4]. Much of the broader claims in that literature come from lab work, not people.
Our read: none of this establishes that lion's mane improves cognition. One small trial in people with mild cognitive impairment saw higher scores while taking it, and the trials in healthy young adults saw little. We are not making any claims about memory, focus or brain health, and neither should a can.
Kanna and lion's mane side by side
| Kanna | Lion's mane | |
|---|---|---|
| What it is | Succulent, Sceletium tortuosum, native to South Africa [6] | Edible mushroom, Hericium erinaceus [4] |
| Human trials we reviewed | Several small trials in healthy adults, mostly Zembrin [7][8][9][12] | Small trials in older adults with mild cognitive impairment and in healthy young adults [1][2][3] |
| Doses studied | 8 to 25 mg per day of one extract [12][9] | About 1.8 to 3 g per day, in different forms [1][2][3] |
| Overall evidence | Described as mixed in a 2026 review [10] | Small and mixed, with some company-linked authorship [2][3][4] |
| Main safety notes | Headache and upset stomach; possible interactions with serotonergic medicines; pregnancy data lacking [5] | Stomach discomfort, headache, allergic reactions listed; often unreported [4] |
Is there research on taking them together?
Not that we could find.
We searched for human trials combining Sceletium and Hericium and found none. That means any claim that the two "work together" or "amplify" each other is unsupported by published human data. Each ingredient has a different proposed mechanism: lab work points to kanna acting on the serotonin transporter and PDE4 [13], while the lion's mane literature we reviewed centers on cognitive tests and, in the preclinical work, nerve-growth-related pathways such as BDNF [4]. Different does not mean complementary. It means unstudied together.
How do label doses compare with studied doses?
They are hard to compare, because the form of the ingredient differs from study to study and from can to can.
Look at how varied the lion's mane trials are. One used tablets of 96% dry powder [1]. One used capsules of a proprietary blend and did not specify whether it was fruiting body or mycelium [11]. One used a 10:1 fruiting-body extract [3]. Those are three different materials. A drink that lists "3,000 mg lion's mane" does not tell you which of them you are getting unless the brand says so. Kanna has the same problem: the human trials used 8 to 25 mg of a specific standardized extract, and milligrams of other extracts are not interchangeable [12][6]. See kanna dosage for how to read that.
Disclosure: kannadrinks.com is published by Psilly Goose. Its Silly can lists 35 mg of kanna (extract standardization not stated) and 3,000 mg of lion's mane, with no caffeine; our ranking shows how that compares with other cans, on the same terms as everyone else.
What safety points apply?
Kanna's main caution is medicine interactions; lion's mane's safety data are thin.
For kanna, WebMD flags possible concern with MAOIs, SSRIs, SNRIs, tricyclic antidepressants, antipsychotics, triptans and St. John's wort, and says it is not known how sceletium might affect pregnancy [5]. For lion's mane, the 2025 review lists stomach discomfort, headache and allergic reactions as potential side effects [4]. We did not find reliable data on lion's mane in pregnancy or alongside medicines in what we reviewed, so the absence of warnings is not the same as safety.
Because we found no studies of the two taken together, a conversation with a doctor or pharmacist is the sensible first step if you take any medication, are pregnant or nursing, or have a mushroom allergy. The same goes for combining any botanical drink with alcohol, which we do not suggest. More in is kanna safe. And if you want to know how drinks differ from capsules for these ingredients, read kanna drinks vs capsules.
This page is general information, not medical advice. These statements have not been evaluated by the FDA. Kanna and lion's mane products are not intended for any disease or health condition.
References
- Mori K, Inatomi S, Ouchi K, Azumi Y, Tuchida T. Improving effects of the mushroom Yamabushitake (Hericium erinaceus) on mild cognitive impairment: a double-blind placebo-controlled clinical trial. Phytother Res 2009;23(3):367-72. PubMed
- Docherty S, Doughty FL, Smith EF. The acute and chronic effects of lion's mane mushroom supplementation on cognitive function, stress and mood in young adults: a double-blind, parallel groups, pilot study. Nutrients 2023;15(22):4842. PubMed
- Surendran G, et al. Acute effects of a standardised extract of Hericium erinaceus (Lion's Mane mushroom) on cognition and mood in healthy younger adults: a double-blind randomised placebo-controlled study. Front Nutr 2025;12:1405796. PubMed
- Menon A, Jalal A, Arshad Z, Nawaz FA, Kashyap R. Benefits, side effects, and uses of Hericium erinaceus as a supplement: a systematic review. Front Nutr 2025;12:1641246. PubMed
- WebMD. Sceletium: Uses, side effects, interactions. webmd.com
- 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
- 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
- Docherty S, et al. 2023 (full text of reference 2, including individual task results and product form). PubMed Central
- 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
- 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
Frequently asked questions
Why are kanna and lion's mane in the same drink?
Brands pair them because both are marketed as botanicals for focus and calm. The pairing is a product choice. In our searches we found no human study that tested kanna and lion's mane together.
Is there human research on lion's mane?
Yes, but it is small and mixed. A 30-person trial in older adults with mild cognitive impairment found higher scores on a cognitive scale after 16 weeks [1], while a 41-person trial in healthy young adults found one faster task result alongside null and negative findings [2]. A third small trial found no overall effect on cognition or mood [3].
Does lion's mane improve memory?
The studies do not show that clearly. One trial measured worse delayed word recall in the lion's mane group at four weeks [2], and an acute trial found no effect on composite cognition [3]. Results varied by outcome and population.
Are there side effects of lion's mane?
A 2025 systematic review lists stomach discomfort, headache and allergic reactions as potential side effects and notes they are commonly unreported [4]. Evidence on safety is thin.
Is it safe to take kanna and lion's mane together?
We found no studies of the combination. Kanna has a known caution with serotonergic medicines such as SSRIs [5], so check with a doctor, especially if you take medication or are pregnant or nursing.