Drug & supplement interaction

Sceletium + Cetirizine

Cetirizine brand names: Cetirizine, Zyrtec, Quzyttir.

Moderate Interaction
Medically reviewed by · Updated October 2026
The bottom line Moderate

Sceletium has a moderate interaction with Cetirizine. Theoretically, concomitant use of sceletium and CNS depressants might result in additive sedative effects.

Read the full interaction report
SeverityModerate
LikelihoodPossible
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Sceletium and Cetirizine

Here is the interaction we found between these two, with the evidence behind it.

Moderate

CNS DEPRESSANTS

Why this applies to Cetirizine

Cetirizine falls under CNS DEPRESSANTS — the group Sceletium interacts with.

Theoretically, concomitant use of sceletium and CNS depressants might result in additive sedative effects.
Some evidence suggests that sceletium has sedative properties.
Severity Moderate Likelihood Possible Evidence D

Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's the short version: both kanna (Sceletium) and cetirizine (Zyrtec) can each make you a little drowsy on their own. Cetirizine isn't a prodrug, so this isn't about one changing how the other is broken down. The concern is simpler: their calming effects may stack up. Kanna appears to have mild sedative properties, and even though cetirizine is a 'non-drowsy' type antihistamine, it still makes some people sleepy.

Put them together and you might feel extra tired, foggy, or slow to react, which matters for driving or focusing. Honestly, this is a theoretical concern based on how each behaves, not strong proof. Still, if you notice unusual sleepiness, go easy and check in with your pharmacist or doctor.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Smith MT, Crouch NR, Gericke N, Hirst M. Psychoactive constituents of the genus Sceletium N.E.Br. and other Mesembryanthemaceae: a review. J Ethnopharmacol 1996;50:119-30. PubMed

What These Ratings Mean

Every interaction above is graded three ways — here’s the key to each label.

Severity how clinically significant the interaction is
Major

Clinically significant. Avoid the combination, or use only under close professional supervision.

Moderate

Usually worth avoiding or managing — may need monitoring, a dose change, or timing apart.

Minor

Generally not serious. Be aware of it and mention it to your pharmacist.

Likelihood how strong the evidence is that the interaction actually happens in people
  • LikelyWell-controlled human studies have demonstrated the likely existence of this interaction.
  • ProbableInteraction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports.
  • PossibleInteraction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.
  • UnlikelyInteraction has been demonstrated in animal or in lab research but has been shown not to occur in humans.
Evidence the quality of the studies behind the rating (graded A–D)
  • AHigh-quality meta-analysis (quantitative systematic review).
  • BCase-control study.
  • CConsensus.
  • DAnecdotal evidence.

These ratings are for information only. Never start, stop, or otherwise change your therapy before speaking with your provider.

Keep it in perspective

Sceletium Also Interacts With Other Medications

Sceletium has 247 moderate known drug interactions in our database — the Cetirizine one above is one of them. If you take anything else, check it against the full list below.

Moderate 247 No known interaction 2,583 (incl. Cetirizine)
Taking anything else?

Check Another of Your Medications Against Sceletium

Covers the 2,830 medications we’ve checked against Sceletium. Pick one to open its full report.

From our Q&A

Questions About Sceletium or Cetirizine

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Sceletium or Cetirizine, not necessarily both, but if one is close to what you were about to ask it will usually go further than a database entry can:

Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.

Everything else you take

See Every Supplement That Interacts With Cetirizine

This page covers Sceletium only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Cetirizine page lists 100 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: 1,4-butanediol (major), Activated Charcoal (major), Beer (major), Gamma-hydroxybutyrate (ghb) (major) and Kava (major).

By severity: 7 major · 78 moderate · 15 minor.

From our pharmacist’s overview on the Cetirizine page

“Cetirizine (Zyrtec) treats allergies, but even this newer antihistamine can make some people drowsy, and that weak spot is where most of its 100 documented supplement interactions land. Seventy-eight of the ingredients on this page add their own sedative pull on top of the drug's, and 7 of the 100 rate major, so treat this list with re…”

Reviewed by 2 · Jul 18, 2026

Open the Cetirizine interaction page

One more smart check

Taking Sceletium as Part of a Dietary Supplement Product? Check It for Interactions

We hold 132 real supplement products containing Sceletium, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Sceletium. Your product may carry other ingredients that interact with Cetirizine too, on top of Sceletium — and those would not show on this page. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Sceletium and Cetirizine Sit Against Everything Else

Out of every supplement and medication people look up on HelloPharmacist, here is where these two land this week — and which way each has been moving.

Supplement Sceletium
Top half

#488 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Cetirizine
Top 25%

#589 of 2,830 medications looked up here in the last 7 days

29 days ago today

Position among everything looked up on this site, not a measure of how commonly either one is used or how important it is. A supplement can climb this list because of a news story. It counts every request to the page, automated ones included, and nothing here identifies anyone.

Supplement

About Sceletium

What is Sceletium?

  • Anxiety and stress
  • Low mood
  • Mental focus and cognition
  • Relaxation
  • Traditional use as a mood lifter

Sceletium (often sold as 'kanna') is a South African plant traditionally used to ease stress and lift mood. Early human studies are small and short, so its benefits are not well proven. Talk to your pharmacist or doctor before trying it, and avoid it during pregnancy and breastfeeding.

Read the full Sceletium monograph & all interactions
Medication

About Cetirizine Injection

What Is Cetirizine Injection Used For?

Brand names: Cetirizine, Zyrtec, Quzyttir

Cetirizine Injection (sold as Quzyttir) treats acute urticaria, which means sudden-onset hives. It is for adults and children 6 months of age and older.

Quzyttir is not recommended for children under 6 years old who have kidney or liver problems.

See full Cetirizine Injection drug information
Keep checking

Other Drugs & Sceletium

Browse every other medication we’ve checked against Sceletium — both the ones with a known interaction and the ones without. Select any drug for the full detail.

0Major
247Moderate
0Minor
2,582No known interaction
247 Moderate 2,582 No interaction
Moderate

247 interactions

Showing 60 of 247 moderate interactions — see all 247 on the Sceletium page.

No interaction 2,582 drugs checked — show the list

We also checked Sceletium against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 2,582 medications checked with no known interaction — see the full Sceletium list.

See the full Sceletium interactions page
See every supplement checked against Cetirizine, ranked by severity
Sources

Sources & How We Checked

Interaction details are evidence-graded and sourced from the Natural Medicines database. The medication overview comes from MedlinePlus.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

Keep exploring
Sceletium monograph › Uses, safety, and every drug interaction in one place Cetirizine supplement interactions › Every supplement checked against Cetirizine, ranked by severity Cetirizine Injection drug information › The full plain-English guide to this medication Supplement interaction checker › Check any supplement or product against your medications Browse medications A–Z › Every drug we've checked against herbs & supplements Ask a pharmacist › Free, personal answer from our licensed team
Pharmacist Counseling Corner

Taking Sceletium and Cetirizine Together: Common Questions

Can you take Sceletium with Cetirizine?
There is a moderate interaction, so it may be acceptable with monitoring or timing changes — but check with your pharmacist first. Read the full details on this page and confirm with your pharmacist before combining them.
How serious is the Sceletium and Cetirizine interaction?
We rate it Moderate. This combination may require monitoring, a dose adjustment, or separating the times you take each one. Consult your pharmacist before using them together.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Still Have a Question About Cetirizine and Sceletium?

Our pharmacists answer your medication & supplement questions — free.

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This information is for education only and is not a substitute for professional medical advice. Always check with your pharmacist or doctor before starting, stopping, or combining supplements and medications.