Drug & supplement interaction

Sceletium + Nirmatrelvir, Ritonavir

Nirmatrelvir, Ritonavir brand name: Paxlovid.

No Known Interaction
Medically reviewed by · Updated July 2026 · Pair last verified Sep 13, 2026
The bottom line No known interaction

We found no known interaction between Sceletium and Nirmatrelvir, Ritonavir in our sources. Absence of a documented interaction is not the same as proven safety, and does not guarantee one does not exist. Do not start, stop, or change a medication or supplement based on this page; confirm with your pharmacist or doctor first.

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Interaction report

Sceletium and Nirmatrelvir, Ritonavir

We checked these two against our interaction database. Here is what we found.

No Known Interaction Found

We did not find a documented interaction between Nirmatrelvir, Ritonavir and Sceletium in our sources. This does not guarantee that the combination is completely free of risk — there is often limited research on supplements and herbal products, especially around drug interactions.

If you decide to take both, the practical routine is simple: add one new thing at a time and note the date you started it. If the combination is going to disagree with you, it usually shows in the first days to a couple of weeks — and a start date turns “I’ve been feeling off” into something a pharmacist can actually work with. Do not stop a prescribed medicine on your own.

Always talk with your pharmacist or doctor before making changes to your medications or supplements, particularly if you take several medications or have an ongoing health condition.

Sceletium safety at a glance

Sceletium overall Use caution It appears generally tolerable in small studies, but long-term safety is not well established.
Pregnancy Avoid There is not enough safety information, so it is best avoided during pregnancy.
Breastfeeding Avoid Safety data are lacking, so avoid use while breastfeeding.

Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Nirmatrelvir, Ritonavir and Sceletium? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Nirmatrelvir, Ritonavir

Interactions in our licensed database are recorded against drug classes, not just single drug names. Nirmatrelvir, Ritonavir is filed under 7 classifications — including cytochrome p450 3a4 (cyp3a4) inhibitors, hepatotoxic drugs, cytochrome p450 3a4 (cyp3a4) substrates. Sceletium has documented interactions with 1 drug class — the most serious being cns depressants (moderate) — and none of Nirmatrelvir, Ritonavir’s classifications are among them.

Classification data comes from our licensed Natural Medicines dataset. A medication can belong to classes beyond those recorded there, so this describes how the check was run — it is not a safety guarantee.

Keep it in perspective

Sceletium Does Interact With Other Medications

Sceletium has 248 moderate known drug interactions in our database — Nirmatrelvir, Ritonavir isn’t one of them. If you take anything else, check it against the full list below.

Moderate 248 No known interaction 2,582 (incl. Nirmatrelvir, Ritonavir)
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.

What to actually watch for

What Sceletium Itself Has Been Linked To

This is not an interaction — nothing below involves Nirmatrelvir, Ritonavir. It is the side-effect record for Sceletium on its own, from the licensed Natural Medicines monograph. If something new turns up after you add Sceletium, this list is the first place to look. 2 entries are worth acting on rather than waiting out — marked below.

  • Low mood Worth acting on Additional detail

    “Orally, a sceletium extract has been reported to cause anxiety, headache, insomnia, and irritability. There are also anecdotal reports that chewing sceletium can cause headache, depression, and listlessness. Additionally, anecdotal reports suggest that sceletium can cause euphoric effects when inhaled or taken orally in high doses.”

    Sceletium · Natural Medicines adverse-effect record, reported in anxiety.

    3 sources cited
    1. 106745. Gericke J, Lekhooa M, Steyn SF, Viljoen AM, Harvey BH. An acute dose-ranging evaluation of the antidepressant properties of Sceletium tortuosum (Zembrin®) versus escitalopram in the Flinders Sensitive Line rat. J Ethnopharmacol. 2022 Feb 10;284:114550. do PubMed
    2. 17580. 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
    3. 100649. Meyer GMJ, Wink CSD, Zapp J, Maurer HH. GC-MS, LC-MS(n), LC-high resolution-MS(n), and NMR studies on the metabolism and toxicological detection of mesembrine and mesembrenone, the main alkaloids of the legal high "Kanna" isolated from Sceletium tortuosum
  • Raised blood pressure Worth acting on Additional detail

    “Orally, a sceletium extract has been reported to cause hypertension.”

    Sceletium · Natural Medicines adverse-effect record, reported in hypertension.

    1 source cited
    1. 106745. Gericke J, Lekhooa M, Steyn SF, Viljoen AM, Harvey BH. An acute dose-ranging evaluation of the antidepressant properties of Sceletium tortuosum (Zembrin®) versus escitalopram in the Flinders Sensitive Line rat. J Ethnopharmacol. 2022 Feb 10;284:114550. do PubMed
  • Mood changes or irritability / Anxiety or restlessness / Trouble sleeping / Headache Additional detail

    “There is currently a limited amount of information on the adverse effects of sceletium. A thorough evaluation of safety outcomes has not been conducted.

    Most Common Adverse Effects:

    Orally: Anxiety, headache, insomnia, irritability, and nausea.”

    Sceletium · Natural Medicines adverse-effect record, reported in anxiety.

  • Reduced appetite Additional detail

    “Orally, a sceletium extract has been reported to cause nausea. There are anecdotal reports that chewing sceletium can cause loss of appetite.”

    Sceletium · Natural Medicines adverse-effect record, reported in nausea and vomiting.

    2 sources cited
    1. 106745. Gericke J, Lekhooa M, Steyn SF, Viljoen AM, Harvey BH. An acute dose-ranging evaluation of the antidepressant properties of Sceletium tortuosum (Zembrin®) versus escitalopram in the Flinders Sensitive Line rat. J Ethnopharmacol. 2022 Feb 10;284:114550. do PubMed
    2. 17580. 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
  • Nausea Additional detail

    Recorded for Sceletium in the same Natural Medicines adverse-effect record shown under Mood changes or irritability / Anxiety or restlessness / Trouble sleeping / Headache above.

Everything above comes from the Natural Medicines adverse-effect record for Sceletium — expand a row for the licensed statement it rests on. We read the ADVERSE REACTIONS section of Nirmatrelvir, Ritonavir’s FDA label too, and the two lists don’t meaningfully overlap — which is why no Nirmatrelvir, Ritonavir column appears here.

Everything else you take

See Every Supplement That Interacts With Nirmatrelvir, Ritonavir

This page covers Sceletium only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Nirmatrelvir, Ritonavir page lists 176 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Beer (major), Grapefruit (major), Siberian Cocklebur (major) and St. John's Wort (major).

By severity: 6 major · 134 moderate · 36 minor.

From our pharmacist’s overview on the Nirmatrelvir, Ritonavir page

“Paxlovid (nirmatrelvir and ritonavir) deserves genuine care around supplements, mostly because its ritonavir component strongly blocks the liver enzyme CYP3A4. The bulk of this list is made up of ingredients that enzyme normally clears, so their levels can climb unpredictably during the five-day course.”

Reviewed by 2 · Jul 18, 2026

Open the Nirmatrelvir, Ritonavir 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. Even though Sceletium itself has no known interaction with Nirmatrelvir, Ritonavir, another ingredient on your label might. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Sceletium and Nirmatrelvir, Ritonavir 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

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

29 days ago today
Medication Nirmatrelvir, Ritonavir
Top 10%

#145 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.

Where does our data come from?
  • Source: the Natural Medicines (TRC Healthcare) clinical database — the evidence-graded professional reference for herb & supplement interactions.
  • Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every Sceletium reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Sceletium and Nirmatrelvir, Ritonavir records this page draws on were last updated July 10, 2026.
  • What “no known interaction” means: no documented interaction in the sources above — not a guarantee of safety. Supplements are studied far less than prescription drugs, so we say exactly what the evidence supports, and nothing more.
Data structure & sourcing designed and verified by .
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.

Sceletium tortuosum · Aizoaceae · Aerial parts (leaves, stems, and flowers), often fermented · Capsules, tablets, powders, tinctures, chewed plant material, and tea

An interaction check asks whether these two react with each other — it does not ask whether Sceletium is a good idea for someone in your situation. Here is what our Sceletium record says about it on its own.

Sceletium: dosing

There is no official, well-established dose for Sceletium. Products differ greatly in their strength and in how they are prepared and standardized.If you choose to use it, follow the directions on the product label and do not exceed the suggested amount.

From our Sceletium monograph — the full record covers uses, side effects and every documented interaction.

Read the full Sceletium monograph & all interactions
Medication

About Nirmatrelvir and Ritonavir

What Is Nirmatrelvir and Ritonavir Used For?

Brand name: Paxlovid

Paxlovid is approved to treat mild-to-moderate COVID-19 in adults who are at high risk of progressing to severe disease — meaning hospitalization or death. It is intended for people who already have symptoms and a confirmed COVID-19 diagnosis.

Paxlovid is not approved to prevent COVID-19 before or after exposure. It is a treatment, not a preventive medication.

See full Nirmatrelvir and Ritonavir 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
248Moderate
0Minor
2,581No known interaction
248 Moderate 2,581 No interaction
Moderate

248 interactions

Showing 60 of 248 moderate interactions — see all 248 on the Sceletium page.

No interaction 2,581 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 2,581 medications checked with no known interaction — see the full Sceletium list.

See the full Sceletium interactions page
See every supplement checked against Nirmatrelvir, Ritonavir, ranked by severity
Evidence & sources

Sceletium References

The 3 references that drive our Sceletium monograph and interaction data, from the evidence-graded Natural Medicines (TRC Healthcare) database. Citations with a link open the study on PubMed or the publisher’s site.

  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
  2. Meyer GMJ, Wink CSD, Zapp J, Maurer HH. GC-MS, LC-MS(n), LC-high resolution-MS(n), and NMR studies on the metabolism and toxicological detection of mesembrine and mesembrenone, the main alkaloids of the legal high "Kanna" isolated from Sceletium tortuosum
  3. Gericke J, Lekhooa M, Steyn SF, Viljoen AM, Harvey BH. An acute dose-ranging evaluation of the antidepressant properties of Sceletium tortuosum (Zembrin®) versus escitalopram in the Flinders Sensitive Line rat. J Ethnopharmacol. 2022 Feb 10;284:114550. do PubMed

Medication overviews come from MedlinePlus (NIH); supplement label data from the NIH Dietary Supplement Label Database. Content is written and reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

Pharmacist Counseling Corner

Taking Sceletium and Nirmatrelvir, Ritonavir Together: Common Questions

Is it safe to take Sceletium with Nirmatrelvir, Ritonavir?
We do not list a known interaction between Sceletium and Nirmatrelvir, Ritonavir. That does not guarantee the combination is risk-free, so confirm with your pharmacist or doctor — especially if you take other medications or have a health condition.
How was the Sceletium and Nirmatrelvir, Ritonavir combination checked?
Interactions in our licensed database are recorded against drug classes. Nirmatrelvir, Ritonavir is filed under 7 classifications, and Sceletium has documented interactions with 1 drug class — none of Nirmatrelvir, Ritonavir's classifications are among them. A medication can belong to classes beyond those recorded in our dataset, so this describes how the check was run rather than guaranteeing safety.
Does Sceletium interact with any other medications?
Yes. Sceletium has 248 documented drug interactions in our database — Nirmatrelvir, Ritonavir is simply not one of them. If you take anything else, it is worth checking each one; they are all listed on this page.
Does Nirmatrelvir, Ritonavir interact with any supplements?
Yes. Nirmatrelvir, Ritonavir has documented interactions with 176 supplements in our database — Sceletium is not one of them. The Nirmatrelvir, Ritonavir interaction page linked on this page lists every one, ranked by severity.

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

Where next

Keep Exploring

Sceletium monograph Uses, safety profile, and every drug interaction in one place Nirmatrelvir and Ritonavir drug information The full plain-English guide to this medication Nirmatrelvir, Ritonavir supplement interactions Every supplement checked against Nirmatrelvir, Ritonavir, ranked by severity Supplement interaction checker Check any supplement or product against your medications Browse medications A–Z Every drug we’ve checked against herbs & supplements References The 3 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Nirmatrelvir, Ritonavir and Sceletium?

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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.