Drug & supplement interaction

Rauvolfia Vomitoria + Ondansetron

Ondansetron brand name: Zofran.

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

Rauvolfia Vomitoria has a moderate interaction with Ondansetron. Theoretically, Rauvolfia vomitoria might increase the levels and clinical effects of CYP2D6 substrates.

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

Rauvolfia Vomitoria and Ondansetron

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

Moderate

CYTOCHROME P450 2D6 (CYP2D6) SUBSTRATES

Why this applies to Ondansetron

Ondansetron falls under CYTOCHROME P450 2D6 (CYP2D6) SUBSTRATES — the group Rauvolfia Vomitoria interacts with.

Theoretically, Rauvolfia vomitoria might increase the levels and clinical effects of CYP2D6 substrates.
Rauvolfia vomitoria contains small amounts of the drug yohimbine. In vitro research shows that yohimbine inhibits CYP2D6 enzyme activity.
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 gist for your Zofran (ondansetron): this anti-nausea medicine is partly cleared by a liver enzyme called CYP2D6. Rauvolfia vomitoria contains a little yohimbine, and in lab (test tube) studies yohimbine can slow that enzyme down. If that happened in your body, ondansetron could break down a bit more slowly and hang around longer, which in theory could nudge up side effects like headache, constipation, dizziness, or tiredness.

Honestly, this is a theoretical concern based only on lab research, not real patient cases, so I wouldn't lose sleep over it. Ondansetron is not a prodrug, so it isn't weakened here. Still, Rauvolfia is a potent herb on its own, so please check with your pharmacist or doctor before combining them.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. VandenBrink, B. M., Foti, R. S., Rock, D. A., Wienkers, L. C., and Wahlstrom, J. L. Prediction of CYP2D6 drug interactions from in vitro data: evidence for substrate-dependent inhibition. Drug Metab Dispos. 2012;40(1):47-53. 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

Rauvolfia Vomitoria Also Interacts With Other Medications

Rauvolfia Vomitoria has 230 major, 522 moderate, 87 minor known drug interactions in our database — the Ondansetron one above is one of them. If you take anything else, check it against the full list below.

Major 230 Moderate 522 Minor 87 No known interaction 1,991 (incl. Ondansetron)
Taking anything else?

Check Another of Your Medications Against Rauvolfia Vomitoria

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

From our Q&A

Questions About Rauvolfia Vomitoria or Ondansetron

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Rauvolfia Vomitoria or Ondansetron, 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 Ondansetron

This page covers Rauvolfia Vomitoria only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Ondansetron page lists 195 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Grapefruit (major), Lithium (major), St. John's Wort (major) and 1,3-dmaa (moderate).

By severity: 4 major · 145 moderate · 46 minor.

From our pharmacist’s overview on the Ondansetron page

“Ondansetron (Zofran) often stands between you and relentless nausea from chemotherapy or surgery, so read this page carefully. Four of the 195 ingredients rate major.”

Reviewed by 2 · Jul 18, 2026

Open the Ondansetron interaction page

One more smart check

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

We hold 17 real supplement products containing Rauvolfia Vomitoria, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Rauvolfia Vomitoria. Your product may carry other ingredients that interact with Ondansetron too, on top of Rauvolfia Vomitoria — 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 Rauvolfia Vomitoria and Ondansetron 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 Rauvolfia Vomitoria
Steady interest

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

29 days ago today
Medication Ondansetron
Steady interest

#1,894 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 Rauvolfia Vomitoria

What is Rauvolfia Vomitoria?

  • High blood pressure
  • Anxiety and agitation
  • Sleep problems
  • Mental health symptoms (traditional use)
  • Fever and general ailments

Rauvolfia vomitoria is an African shrub whose root contains powerful alkaloids, including reserpine, that have historically been used for high blood pressure and agitation. Because these compounds can strongly affect blood pressure, mood, and the nervous system, the plant can cause serious side effects and is not a casual supplement. Always talk to a doctor or pharmacist before using it.

Read the full Rauvolfia Vomitoria monograph & all interactions
Medication

About Ondansetron

What Is Ondansetron Used For?

Brand name: Zofran

Ondansetron is used to prevent nausea and vomiting in several situations. Oral forms (tablets, orally disintegrating tablets, and oral solution) are approved to prevent nausea and vomiting from highly or moderately emetogenic (nausea-causing) cancer chemotherapy, from radiation therapy to the abdomen or whole body, and from surgery.

Ondansetron injection (given intravenously or intramuscularly in a clinical setting) is approved to prevent nausea and vomiting from emetogenic cancer chemotherapy — including high-dose cisplatin — in adults and children as young as 6 months old, as well as to prevent postoperative nausea and vomiting.

See full Ondansetron drug information
Keep checking

Other Drugs & Rauvolfia Vomitoria

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

230Major
522Moderate
87Minor
1,990No known interaction
230 Major 522 Moderate 87 Minor 1,990 No interaction
Major

230 interactions

Showing 60 of 230 major interactions — see all 230 on the Rauvolfia Vomitoria page.

Moderate

522 interactions

Showing 60 of 522 moderate interactions — see all 522 on the Rauvolfia Vomitoria page.

Minor

87 interactions

Showing 60 of 87 minor interactions — see all 87 on the Rauvolfia Vomitoria page.

No interaction 1,990 drugs checked — show the list

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

Showing the 60 most looked-up of 1,990 medications checked with no known interaction — see the full Rauvolfia Vomitoria list.

See the full Rauvolfia Vomitoria interactions page
See every supplement checked against Ondansetron, 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
Rauvolfia Vomitoria monograph › Uses, safety, and every drug interaction in one place Ondansetron supplement interactions › Every supplement checked against Ondansetron, ranked by severity Ondansetron 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 Rauvolfia Vomitoria and Ondansetron Together: Common Questions

Can you take Rauvolfia Vomitoria with Ondansetron?
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 Rauvolfia Vomitoria and Ondansetron 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 Ondansetron and Rauvolfia Vomitoria?

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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.