Sceletium tortuosum (or kanna, channa, kougoed) is a psychoactive succulent plant native to South Africa. San hunter-gatherers (or Bushmen), as well as Khoi pastoralists, have used kanna for millennia, before written reports of the uses of these plants by European explorers and settlers emerged. These indigenous peoples have used kanna – the Khoi word for the plant – as a masticatory (something you chew for pleasure or to increase saliva). The literal translation of the Afrikaans name for the plant, ‘kougoed’, is ‘something to chew’. Kanna has also traditionally been used for the relief of thirst and hunger, to combat fatigue, as medicines, and for social and spiritual purposes.
Despite increasing interest in the mood-enhancing, antidepressant, and anxiolytic potential of kanna, it is still a relatively unknown drug. The kanna subreddit, for instance, has only 4.9k followers at the time of writing. It is common to find it sold in headshops in the Netherlands. It is also sold on some online marketplaces like eBay and Etsy, usually by vendors who deal in legal psychoactive and psychedelic plants. You can find the plant in powder form, either fermented, unfermented, or as an extract.
The Antidepressant and Anxiety-Reducing Effects of Kanna
Outside of traditional use, kanna has attracted attention as a possible source of anxiolytic and antidepressant effects. Indeed, many individuals find that kanna helps to enhance well-being, resulting in a state of positive mood while reducing anxiety, depression, stress, and tension. Research, including double-blind, placebo-controlled clinical trials, have indeed shown that kanna can decrease anxiety, which can be seen through the plant’s non-placebo effects on anxiety-related activity in the amygdala (a core brain area that helps to detect threat, activate fear responses, and process memories associated with fear).
Kanna is thought to relieve depression and anxiety because it is a serotonin reuptake inhibitor (SRI), as well as a selective phosphodiesterase-4 (PDE4) inhibitor. A 2013 study on kanna, published in Neuropsychopharmacology, concluded:
These results demonstrate, for the first time, the attenuating effects of S. tortuosum on the threat circuitry of the human brain and provide supporting evidence that the dual 5-HT reuptake inhibition and PDE4 inhibition of this extract might have anxiolytic potential by attenuating subcortical threat responsivity.
Selective serotonin reuptake inhibitors (SSRIs) are widely used for the treatment of anxiety and depressive disorders. These compounds include antidepressants like fluoxetine (Prozac), citalopram (Celexa), escitalopram (Lexapro), paroxetine (Paxil), and sertraline (Zoloft).
SSRIs, like Prozac, are a specific kind of SRI: they inhibit the reuptake of serotonin to a particular or relative degree compared to other drugs. Inhibiting the reuptake of serotonin means that extracellular serotonin (the serotonin outside the nerve cells) is not reabsorbed by these nerve cells in the brain, as it normally would be after serotonin has carried a message between cells. Instead, the SSRI increases the amount of this neurotransmitter present in the synapse (the gap between cells), which magnifies its effects.
The ‘selective’ in SSRI does mean these drugs only act on serotonin; it means they are more selective to serotonin than other neurotransmitters. In contrast to traditional SSRI antidepressants, kanna’s pharmacological action is dual: PDE4 and serotonin reuptake inhibition.
Repeated treatment with SSRIs can actually upregulate PDE4 (increase the cellular response to it), which reduces the sensitivity to SSRIs in response to long-term treatment, suggesting that the dual effects of serotonin reuptake and PDE4 inhibition may be a promising mental health treatment. The combination of inhibiting both serotonin reuptake and PDE4 could offer therapeutic advantages compared to taking an SSRI or PDE4 inhibitor alone. A 2009 study from Cashman et. al, for example, found that a “dual PDE4 inhibitor/SSRI was significantly more effective than the individual SSRI alone”.
If kanna can be used as an effective antidepressant and anxiolytic, this would be an attractive option for many, as it would mean you could avoid the host of unpleasant side effects you can get from taking antidepressants and anti-anxiety medication.
The Active Alkaloids in Kanna
Kanna contains about 1-1.5% total alkaloids. These alkaloids include mesembrine, mesembrenone, mesembrenol, and tortuosamine. Mesembrine and mesembrenone are the main alkaloids, with mesembrine typically being the most abundant. There is about 0.3% mesembrine in the roots and 0.86% in the leaves, stems, and flowers of the plant. Mesembrine serves as an SRI with less prominent inhibitory effects on PDE4. Mesembrenone, on the other hand, has more balanced inhibitory effects on serotonin reuptake and PDE4.
Kanna is often fermented for two reasons: to increase the mesembrine content (offering stronger psychoactive effects) while reducing levels of oxalic acid, which can have potentially harmful effects. The KhoiSan people (including both the pastoral Khoi and hunter-gatherer San) have fermented kanna preparations for the sake of psychoactive effects.
Extracts of the plant, which have higher potency, require you to take less of the plant, with differing dosages of extracts depending on their potency; for example, you can find kanna extracts in the 10x-100x range. 100x or 100:1 ratio, as a case in point, means that for every 100 grams of plant material, 1 gram of extract is obtained. This means it is 100 times stronger than the ordinary kanna powder. Kanna extracts can be derived from both unfermented and fermented kanna.
‘Kannabis’: The Unique Combination of Kanna and Cannabis
It is common for users to combine kanna with cannabis, which has been dubbed ‘kannabis’. This is a common combination because kanna helps to potentiate the effects of cannabis while also reducing the anxiety that may be associated with the cannabis high. The anxiety-reducing effects make sense, based on the evidence we have outlined. But why does kanna make cannabis highs more intense? Well, evidence has shown that the alkaloids in kanna also bind to cannabinoid receptors, just as the THC in the cannabis plant does. Thus, kanna and cannabis have a synergistic effect.
Many people report (like on the kanna subreddit) that kannabis has distinct effects, claiming that it changes the cannabis high, making it more euphoric and sedating, as well as even more psychedelic. In fact, this combination predates modern use. William Paterson, as described in his book A Narrative of Four Journeys into the Country of the Hottentots and Caffraria (1789), observed that the indigenous people of South Africa combined kanna with cannabis, leading to strong psychoactive effects:
We now proceeded … to enter into a country which is, perhaps, one of the most barren in the world. This is called the Channa Land: and derives its name from a species of Mezembryanthimum (sic), which is called Channa by the natives, and is exceedingly esteemed among them. They make use of it both in chewing and in smoaking (sic); when mixed with the Dacka (sic) is very intoxicating, and which appeared to be of that species of hemp which is used in the East Indies by the name of Bang.
“Dacka” here refers to ‘dagga’, a term, dating to the 1660s, used in certain areas of Southern Africa to describe cannabis. People today can combine kanna and cannabis in all sorts of ways. Traditionally, prepared dried kanna was often chewed and the saliva swallowed, but there are reports of it also being taken as a tea and a snuff, as well as smoked. People today will use kanna in these ways, as well as using other methods of administration, including sublingually (holding the plant material under the tongue) and vaping (as this avoids the need to inhale smoke).
You can then combine one of these routes of administration with different ways of consuming cannabis (e.g. smoking and edibles). Varying combinations of routes of administration – of both kanna and cannabis – can alter the resulting effects. For example, snorting kanna can lead to a faster onset and stronger, euphoric effects compared to drinking kanna tea. Insufflation has its downsides, though, such as pain or discomfort, getting a blocked nose, possible bleeding, and being stuck with the smell of kanna during the experience. Many users instead like to mix kanna with their cannabis when smoking or vaping.
Vice published a piece on kanna in 2020, with the headline claiming it’s like ‘natural’ MDMA and the writer, Suzannah Weiss, saying it made her “roll like I’d taken MDMA”. During a retreat in LA involving the plant, she was told it would make her feel “warm and fuzzy”. But as Weiss reports:
So, it took me by surprise that about an hour into the ceremony, I was full-on rolling. I felt elated and full of ideas, I wanted to shower everyone with words of affection, and I couldn’t help but share my revelations with anyone who’d listen, nor could I stop grinding my jaw. When I told the leader how familiar this was feeling, she said, “yes, it’s natural MDMA.”
Many users would be hesitant to call kanna ‘natural MDMA’, although it can have MDMA-like effects. But these effects – such as strong feelings of euphoria, tactile enhancement, and stimulation – are really felt when taking higher doses of kanna, as well as when combining it with cannabis. People might compare kanna to a low dose of MDMA, finding it to have noticeable empathogenic effects. Nonetheless, you shouldn’t expect kanna, even in high doses, to reach the subjective quality and levels of euphoria and empathy you get from MDMA.
James Giordano, professor of neurology and biochemistry at Georgetown University Medical Center, has noted kanna’s MDMA-like effects: “You’re going to get euphoric, you’re going to feel really happy and really loving and really chill.” Many people find kanna increases feelings of sociability and the enhancement of music, which, along with its other psychoactive effects, makes it an appealing recreational drug. Some say kanna also enhances sex by making sensations more pleasurable.
It would be mistaken to expect an MDMA experience when taking kanna. They’re certainly not like-for-like. However, kanna has the potential to be used as a less-risky alternative to MDMA (although not all users would agree it’s an adequate substitute). Kanna is less risky because it achieves its psychoactive effects through a different mechanism. Lisa Jerome, in a comprehensive document on MDMA, produced on behalf of the Multidisciplinary Association for Psychedelic Studies (MAPS), highlights:
A large body of research has examined the neurotoxic potential of MDMA, with the general consensus being that MDMA may be neurotoxic to the axons of serotonergic cells at high or repeated doses (Baumann et al. 2007; Cole and Sumnall 2003b). Studies in rodents and nonhuman primates have found that high and repeated doses of MDMA reduce brain serotonin levels and may damage the axons of serotonergic neurons (Cole and Sumnall 2003b). However, lower doses do not appear to do this (Mechan et al. 2006; Wang et al. 2005), and it is not likely that the dosages and regimens found in controlled studies produce these effects.
But besides possible neurotoxic effects, MDMA can also lead to those infamous unpleasant comedowns; plus there is the problem of other, more dangerous drugs (e.g. PMA and PMMA) being missold as MDMA, or MDMA being adulterated with such drugs, which can increase the risk of physical harm and a fatal reaction. Commenting on kanna, Giordano has said, “For euphorigenic effects, for reduction of anxiety, for mood stabilization, it’s a safe compound.” Indeed, researchers discovered that a kanna extract of up to 25 mg consumed daily by healthy adults over a three-month period was well tolerated. The most commonly reported adverse effect was a headache, but this actually had a greater incidence in the placebo group than the kanna-taking group. Still, many users do report headaches being a common side effect of kanna, so this is worth keeping in mind.
There is one crucial risk associated with kanna to be aware of, however. And that’s serotonin syndrome: an excess of serotonin in the brain that can lead to overheating, rapid heartbeat, shaking, and in some cases, death. Because kanna is an SRI, this means (as it does when taking an SSRI antidepressant), you should not mix it with other substances that increase levels of serotonin in the brain, such as MDMA, SSRIs, monoamine oxidase inhibitors (MAOIs), and 5-HTP.
Kanna is relatively inexpensive, which makes it a promising candidate as an antidepressant, anxiolytic, recreational drug, and enhancer of the cannabis high. Not many people have heard of kanna or come across it, but it is a legal high that offers users benefits like stimulation, feelings of empathy, a boost in mood, increased sociability, euphoria, and reduced anxiety, with very few downsides. This unique South African plant, therefore, deserves more public and scientific attention.