Kanna Supplements: Forms, Labels and What the FDA Does and Does Not Do
Capsules, powders, tinctures, teas and drinks all say 'kanna', but they can contain very different things. Here is how to tell them apart.
Kanna supplements are a messy category. "Kanna" on a front label can mean ground leaf, a concentrated extract, a few milligrams of isolated alkaloids, or a fermented preparation, and the milligram number printed beside it means something different each time. This guide explains the forms, how US regulation applies, and which questions are worth asking before you buy anything.
Kanna supplements are products made from Sceletium tortuosum, sold as capsules, powders, tinctures, teas, chews and drinks [5]. In the US the FDA does not approve dietary supplements before sale, and it has not reviewed sceletium for safety and effectiveness [1][4]. Doses are not comparable across products, because plant material and extracts differ in strength [7].
What are kanna supplements?
They are products made from Sceletium tortuosum, a succulent native to South Africa that is also catalogued as Mesembryanthemum tortuosum [10].
The plant has a long history as a chewed, smoked or fermented material, and its main active compounds are mesembrine-type alkaloids [5][6]. A modern supplement is usually a processed version of that plant. For the background, see what is kanna. For the human research, which is small and mostly built on one extract, see what the research shows.
What forms do kanna supplements come in?
A 2021 review lists capsules, gel caps, resin, teas, tinctures, raw powdered plant material and tablets, and WebMD adds liquid extract, gummies and raw leaves [4][5].
| Form | What it usually is | What to watch on the label |
|---|---|---|
| Capsules and tablets | Powder or extract in a measured unit | Whether the milligrams are herb or extract; servings per container |
| Powder | Ground plant, sometimes extract-fortified | Plant part, fermented or not, extract ratio if any |
| Tincture or liquid extract | Plant steeped in alcohol or another solvent | Solvent and the amount of total extract [3] |
| Tea | Dried plant for steeping | Amount of plant per bag or serving |
| Chews and gummies | Extract in a candy base | Other active ingredients; per-piece versus per-pack milligrams |
| Drinks and shots | Extract dissolved or suspended in liquid | Whether the extract is named; per-can versus per-bottle amounts |
We have separate posts coming for capsules, powder, tinctures and tea. For a drinks-versus-capsules comparison today, see kanna drinks vs capsules.
Is it whole herb or an extract?
This is the most important question, because the two can differ many times over in alkaloid content per milligram.
Whole-plant products are ground leaf and stem. Extracts are made by pulling compounds out with a solvent and concentrating them. A review of extract ratios notes that a ratio such as 10:1 means roughly 10 g of dried plant went into 1 g of native extract, and that the ratio describes yield, not potency [7]. Our kanna extract guide covers this in depth.
The plant itself is variable. A review of wild-harvested material describes unpredictable mesembrine-type alkaloid content [5], and chemical profiling studies find population-specific differences between sites [12]. Fermenting the plant, as in traditional "kougoed", changed the alkaloid profile in a controlled study: mesembrine fell from 1.33% to 0.05% while a related alkaloid rose from below the quantitation limit to 0.11% [11].
Are kanna supplements regulated by the FDA?
Yes, but mostly after sale, and the agency does not vet each product first.
The FDA states that under the Dietary Supplement Health and Education Act of 1994 it does not have the authority to approve dietary supplements before they are marketed, and that the firm is responsible for ensuring its product is not adulterated or misbranded [1][2]. Manufacturers must follow good manufacturing practices, which include verifying the identity of dietary ingredients [1][13]. A label may carry a structure or function statement only with the required disclaimer that the FDA has not evaluated it and that the product is not intended for any disease [14].
For kanna specifically, WebMD states the FDA has not reviewed sceletium for safety and effectiveness, is not approving it, and has not tested sceletium products to confirm they contain the ingredients on their labels. It also says some sceletium supplements have contained other ingredients, such as ephedrine [4]. That is a reason to value lot-specific lab reports, covered in how to read a kanna label. Our is kanna legal page covers the federal and Louisiana picture.
Why can't you compare milligrams between kanna supplements?
Because the milligram figure can refer to different things: dried plant, a native extract, an extract with filler added, or isolated alkaloids.
US labeling rules say that for a dried extract the listed weight is the weight of the dried extract, and a liquid extract is listed by the volume or weight of the total extract with the solvent identified [3][15]. Nothing in those rules makes two brands' extracts equivalent. A review in Frontiers in Pharmacology says equivalence of extracts "cannot be determined without a detailed comparison" of solvents and manufacturing processes, and that adding carriers lowers the native extract content [7].
The clinical doses add another layer. A 3-month safety trial used 8 mg and 25 mg daily of Zembrin, a 2:1 standardized extract [8]. A brain-imaging study and a cognition study used 25 mg of the same extract [9][16]. Those results belong to that extract and do not transfer to another product with the same number printed on it. See what Zembrin is and kanna dosage.
How do kanna supplements compare with kanna drinks?
The active ingredient is the same plant; the differences are convenience, flavor and how easy the label is to read.
Capsules and powders tend to carry a clearer per-unit dose and a longer ingredient list that is easy to audit. Drinks are pleasant and replace another beverage, but the per-can amount is often given for an extract of unstated strength. No human study has compared the formats directly, so we make no claim that one works better. For the side-by-side of drinks, see our ranking, which marks "not stated" wherever a brand does not disclose its extract.
What safety points apply to every form?
The same ones: serotonergic medicines, pregnancy and nursing, and limited long-term data.
WebMD lists MAOIs, SSRIs, SNRIs, tricyclic antidepressants, antipsychotics, triptans and St. John's wort as medicines with possible interactions, and says it is not known whether sceletium affects pregnancy or passes into breast milk. Common side effects are headache and upset stomach [4]. In a 3-month trial of 37 healthy adults, vital signs, ECG and lab values did not differ meaningfully from placebo, and headache was more common on placebo [8]. NCCIH adds that "standardized" on a label does not necessarily guarantee quality or consistency, and that many supplements have not been tested in pregnant or nursing women [17]. If you take any prescription medicine, ask a doctor or pharmacist before trying kanna in any form. More at is kanna safe.
What should you check before buying a kanna supplement?
- Is the species named (Sceletium tortuosum or Mesembryanthemum tortuosum) and the plant part stated [3][15]?
- Is it herb or extract, and if extract, which one and at what ratio?
- Is the milligram figure for the extract or for alkaloids?
- Does the brand publish a lab report that matches your lot number?
- Does the label warn about antidepressants and other serotonergic medicines?
- Does it mention a "proprietary blend"? Blends list a total weight, which hides the amount of each ingredient [15].
Each of these is expanded in how to read a kanna label.
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. kannadrinks.com is published by Psilly Goose, a kanna drink maker.
References
- U.S. Food and Drug Administration. Questions and Answers on Dietary Supplements. fda.gov
- U.S. Food and Drug Administration. Dietary Supplements. fda.gov
- 21 CFR 101.36, Nutrition labeling of dietary supplements. law.cornell.edu
- WebMD. Sceletium: Uses, side effects, interactions. webmd.com
- Manganyi MC, et al. A chewable cure "Kanna": biological and pharmaceutical properties of Sceletium tortuosum. Molecules 2021;26(9):2557. PMC
- Olatunji TL, et al. Sceletium tortuosum: a review on its phytochemistry, pharmacokinetics, biological and clinical activities. J Ethnopharmacol 2021;280:114476. PubMed
- Monagas M, et al. Understanding plant to extract ratios in botanical extracts. Front Pharmacol 2022;13:981978. Frontiers
- 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
- 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
- Brendler T, et al. Sceletium for managing anxiety, depression and cognitive impairment: a traditional herbal medicine in modern-day regulatory systems. Curr Neuropharmacol 2021;19(9):1384-1400. PubMed
- Patnala S, Kanfer I. Investigations of the phytochemical content of Sceletium tortuosum following the preparation of "Kougoed" by fermentation of plant material. J Ethnopharmacol 2009. PubMed
- Reddy K, et al. Mass spectrometry metabolomics and feature-based molecular networking reveals population-specific chemistry in some species of the Sceletium genus. Front Nutr 2022;9:819753. PMC
- 21 CFR 111.75, Dietary supplement current good manufacturing practice: component specifications and identity. law.cornell.edu
- U.S. Food and Drug Administration. Notifications for Structure/Function and Related Claims in Dietary Supplement Labeling. fda.gov
- U.S. Food and Drug Administration. Dietary Supplement Labeling Guide: Chapter IV, Nutrition Labeling. fda.gov
- 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
- National Center for Complementary and Integrative Health. Using Dietary Supplements Wisely. nccih.nih.gov
Frequently asked questions
What are kanna supplements?
Kanna supplements are products made from Sceletium tortuosum, a South African succulent, sold as capsules, powders, tinctures, teas, chews and drinks [5][6]. They differ in whether they contain dried plant or an extract, and in how much of the active alkaloids they carry.
Are kanna supplements regulated by the FDA?
Only after they are on sale. The FDA does not approve dietary supplements before they are marketed, and the company is responsible for making sure its product is not adulterated or misbranded [1]. WebMD notes the FDA has not reviewed sceletium for safety and effectiveness and has not tested sceletium products to confirm label contents [4].
Is a kanna extract the same as kanna powder?
No. Powder is ground plant material. An extract is made by pulling compounds out of the plant with a solvent, so the same weight can contain very different amounts of alkaloids [7]. See our guide to kanna extract.
Is 25 mg of kanna the same on every label?
No. The 25 mg dose used in several trials was of one standardized extract, Zembrin [8][9]. A 25 mg figure on another product may be dried herb, a different extract, or alkaloids, so the numbers are not interchangeable. See kanna dosage.
Can I take kanna supplements with antidepressants?
Ask a doctor or pharmacist first. WebMD lists SSRIs, SNRIs, MAOIs, tricyclics, antipsychotics, triptans and St. John's wort as possible interaction concerns [4]. See is kanna safe.