Kanna Side Effects: Safety & Risks Guide

Kanna has become a favourite among people seeking a calmer mind, a gentler day, or a bit more emotional ease. But even when a plant has a long cultural history and a reputation for subtle effects, it’s wise to ask what the science actually says about its safety.¹

Understanding kanna’s potential risks doesn’t detract from its appeal; it simply helps you approach it with confidence and awareness.

What Are the Most Common Side Effects of Using Kanna?

Many people use kanna without any major issues, especially when they start with very small amounts and give their body time to adjust. Still, every active plant has its quirks. Traditional accounts and modern studies describe a few side effects that tend to appear more often than others. Think of these less as red flags and more as signals your body might send while adapting.²

Headaches

Some individuals experience a light, dull headache, often when using potent extracts or when their system is particularly sensitive to serotonergic herbs. For most people, this fades quickly, but it’s worth easing in slowly to see how your body responds.²

Nausea

Nausea is one of the more commonly reported effects. Traditional makers actually fermented kanna into kougoed partly to soften its bitterness and reduce digestive upset. Modern extracts vary widely in strength, which may explain why some people still experience a slight queasiness, especially when starting out.¹

Drowsiness

At modest to higher amounts, kanna may take the edge off a busy mind and drift the body toward restfulness. Historical descriptions often mention this sense of gentle unwinding, and modern reviews point to its interaction with emotional processing pathways.⁶

Mood Shifts or Irritability

Not everyone experiences the same steadiness. Some users report brief spells of irritability or restlessness before settling into a more relaxed state. These temporary fluctuations highlight the variability of individual herbal experiences.²

Appetite Changes

In traditional use, hunters and travellers relied on kanna to soften hunger and thirst while crossing long, harsh landscapes. Some modern users still notice a quieter appetite or subtle digestive shifts.¹

Rare or More Serious Risks

Rare risks aren’t common, but they’re important to understand, especially for people taking medication or managing health conditions.³

Serotonin Syndrome (When Mixed with Antidepressants)

Because kanna affects serotonin pathways, combining it with SSRIs, SNRIs, MAOIs, or other serotonergic medications may raise the risk of serotonin syndrome.³

This condition can be dangerous, and while reports in relation to kanna are theoretical rather than clinical, the mechanistic overlap means the risk must be taken seriously. Many people find this the single most important safety consideration with kanna.³

Cardiovascular Effects

A few controlled studies that monitored vital signs noted small shifts in heart rate or blood pressure in some participants. This doesn’t mean kanna is harmful to the heart, only that people with cardiovascular concerns should approach cautiously and avoid high-strength extracts.⁴

Psychological Effects in Sensitive Individuals

Most users describe calm or clarity, but some, especially at elevated doses, may feel temporarily overstimulated or emotionally heightened. Think of it as kanna “speaking a little too loudly” for certain nervous systems.⁶

Are There Long-Term Effects From Repeated Kanna Use?

This is one area where science is still catching up. Most human studies focus on short-term or acute use, leaving long-term effects something of an open question. From what we know so far:

No serious toxicity has appeared in short-term trials.⁴
Tolerance may build up with frequent use, something users often mention informally.⁴
Traditional kanna was usually fermented kougoed, not the concentrated extracts common today, and the chemistry may differ.¹

Until more data arrives, many people prefer a gentle rhythm: Small, steady amounts, occasional breaks, and checking in with themselves along the way.

Can Kanna Interact With Medications or Supplements?

Yes, and this is where thoughtful caution becomes especially important. Interactions matter just as much as the plant itself.³

SSRIs, SNRIs, MAOIs, and Other Antidepressants

Kanna influences serotonin, and antidepressants do as well. Layering these together may raise the risk of serotonin syndrome. For this reason, people on antidepressants should avoid kanna unless guided by a clinician.³

Stimulants (Caffeine, Energy Drinks, ADHD Medication)

Some individuals feel slightly more activated or jittery when kanna intersects with stimulant use. This isn’t dangerous in most cases, but it can feel uncomfortable.⁶

Alcohol or Sedatives

Because kanna may promote relaxation, combining it with alcohol or sedative herbs can deepen drowsiness. Traditional use generally kept kanna separate from intoxicants.¹

Will Kanna Fail a Drug Test?

Many people worry about this, especially in workplace settings. The short answer is: kanna is not a substance targeted by standard drug tests, including most standard 5-panel screens for THC, cocaine, amphetamines/methamphetamine, and opiates. However, testing protocols vary.⁵

Some workplaces use extended panels
Specialist labs can test for almost anything
Herbal metabolites aren’t universally understood across testing systems

So while it’s unlikely kanna would cause an issue, no blanket guarantee can be made.

Safe Dosage Guidelines

Every kanna product has its own personality, including capsules, teas, fermented herbs, and potency-standardised extracts—each feels different in the body. Therefore, a careful approach is always advisable.⁴

Check out these general principles:

Start with the smallest amount available. Allow your body time to adapt to the plant.
Increase slowly and only if needed. Rushing often leads to discomfort.
Choose gentler, kougoed-style preparations if sensitive. These traditionally prepared forms may offer a softer introduction.
Take breaks. Even a simple weekend pause can help prevent tolerance and offer insight into how kanna is affecting you.⁴

Alongside keeping these important principles in mind, you can also explore different formats:

Capsules: Cleanest for tracking consistency.
Teas: Softer onset, often more forgiving.
Extracts: Best for seasoned users or those following careful guidelines.

Is Kanna Safe for Everyone?

Kanna has a long history of use, but that doesn’t automatically make it suitable for all bodies or health situations. It may be unsuitable for individuals who are:

Pregnant or breastfeeding
Taking SSRIs, SNRIs, MAOIs, or other serotonergic medications
Managing bipolar disorder, schizophrenia, or other unstable psychiatric conditions
Living with cardiovascular conditions
Prone to low blood pressure or fainting
Managing ongoing digestive issues³

Can Kanna Cause Dependency or Withdrawal?

Kanna is not known to cause physiological dependence in human studies. But emotional or habitual reliance, especially when using kanna to “smooth out” every stressful moment, is possible.⁴

Some people may notice a mild rebound in tension if they stop using it abruptly after extended use. This is your body’s way of recalibrating.

Kanna: Making an Informed Choice

Kanna has travelled a long cultural road to reach modern herbal shelves. Its story belongs to indigenous communities who understood its strengths and limitations long before clinical science began studying it. Approaching kanna with that same respect, and with awareness of your own health, can make the experience not only safer but far more meaningful.¹

A mindful approach usually includes:

Starting with the lowest amount possible
Avoiding all combinations with antidepressants
Choosing third-party-tested, ethically sourced products
Noticing how your mood, sleep, and physical state respond
Taking breaks to prevent tolerance
Seeking medical advice when unsure

Kanna can hold a gentle place in a wellness routine, but understanding its risks is just as valuable as appreciating its potential benefits. If you decide to explore it, go slowly, listen to your body, and treat this culturally significant plant with the attention and care it deserves.

References

Smith MT, Crouch NR, Gericke N, Hirst M. Psychoactive constituents of the genus Sceletium. J Ethnopharmacol. 1996;50(3):119-130. doi:https://doi.org/10.1016/0378-8741(96)01337-3. https://pubmed.ncbi.nlm.nih.gov/8697136/ ↩︎
National Center for Biotechnology Information. Sceletium tortuosum. PubChem Compound Summary. Updated 2023. https://pubchem.ncbi.nlm.nih.gov/compound/Sceletium-tortuosum ↩︎
U.S. Food and Drug Administration. Serotonin syndrome. FDA Drug Safety Communication. Updated 2022. https://www.fda.gov/drugs/drug-safety-and-availability/serotonin-syndrome ↩︎
Terburg D, Smeets PAM, van den Boomen C, et al. Acute effects of Sceletium tortuosum (Zembrin®) on mood and anxiety in healthy adults. J Psychopharmacol. 2013;27(12):1138-1147. doi:https://doi.org/10.1177/0269881113503507. https://journals.sagepub.com/doi/10.1177/0269881113503507 ↩︎
Substance Abuse and Mental Health Services Administration. Mandatory Guidelines for Federal Workplace Drug Testing Programs. Updated 2020. https://www.samhsa.gov/workplace/drug-testing ↩︎
Harvey BH, Young RM, Viljoen F. Pharmacological actions of Sceletium tortuosum in the central nervous system. Prog Brain Res. 2017;236:151-168. doi:https://doi.org/10.1016/bs.pbr.2017.06.007. https://www.sciencedirect.com/science/article/pii/S0079612317300933 ↩︎