Drug & supplement interaction

Rauvolfia Vomitoria + Losartan Potassium

Losartan Potassium brand name: Cozaar.

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

Rauvolfia Vomitoria has a moderate interaction with Losartan Potassium. Theoretically, Rauvolfia vomitoria might increase the risk of hypotension.

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

Rauvolfia Vomitoria and Losartan Potassium

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

Moderate

ANTIHYPERTENSIVE DRUGS

Why this applies to Losartan Potassium

Losartan Potassium falls under ANTIHYPERTENSIVE DRUGS — the group Rauvolfia Vomitoria interacts with.

Theoretically, Rauvolfia vomitoria might increase the risk of hypotension.
Rauvolfia vomitoria contains a very small amount of the drug reserpine. Reserpine can reduce both systolic and diastolic blood pressure.
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 simple version: both of these lower blood pressure, just by different routes. Losartan (Cozaar) relaxes your blood vessels by blocking a hormone called angiotensin. Rauvolfia vomitoria contains a small amount of reserpine, which lowers blood pressure by depleting certain nerve chemicals. Stack the two together and you could end up with blood pressure that drops more than you want.

If that happens, you might feel dizzy, lightheaded, tired, or faint, especially when you stand up quickly. This is a theoretical concern based on how reserpine works, not strong human studies, so don't panic. Still, since this herb is potent, please check with your pharmacist or doctor before combining it with your losartan.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Lobay D. Rauwolfia in the Treatment of Hypertension. Integr Med (Encinitas). 2015 Jun;14(3):40-6.
  2. Sheldon MB, Kotte JH. Effect of Rauwolfia serpentina and reserpine on the blood pressure in essential hypertension; a long-term double-blind study. Circulation. 1957 Aug;16(2):200-6.

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 Losartan Potassium 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. Losartan Potassium)
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 Losartan Potassium

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 Losartan Potassium, 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 Losartan Potassium

This page covers Rauvolfia Vomitoria only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Losartan Potassium page lists 253 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), American Hellebore (major), American Mistletoe (major), Grapefruit (major) and St. John's Wort (major).

By severity: 6 major · 205 moderate · 42 minor.

From our pharmacist’s overview on the Losartan Potassium page

“Losartan potassium (Cozaar) treats high blood pressure, and this is a list to respect, because six of its 253 supplement interactions carry a major rating. Most entries do one of two things.”

Reviewed by 2 · Jul 18, 2026

Open the Losartan Potassium 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 Losartan Potassium 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 Losartan Potassium 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
Top half

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

29 days ago today
Medication Losartan Potassium
Top 1%

#15 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 Losartan

What Is Losartan Used For?

Brand name: Cozaar

Losartan treats high blood pressure (hypertension) in adults and children 6 years and older. Keeping blood pressure under control lowers the risk of serious events like stroke and heart attack.

It is also used to reduce the risk of stroke in people who have high blood pressure and left ventricular hypertrophy (an enlarged heart muscle). Note: evidence suggests this stroke-risk benefit may not apply to Black patients. Additionally, losartan treats diabetic nephropathy — kidney damage caused by type 2 diabetes — in people who also have high blood pressure.

See full Losartan 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 Losartan Potassium, 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 Losartan Potassium supplement interactions › Every supplement checked against Losartan Potassium, ranked by severity Losartan 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 Losartan Potassium Together: Common Questions

Can you take Rauvolfia Vomitoria with Losartan Potassium?
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 Losartan Potassium 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 Losartan Potassium 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.