Drug & supplement interaction

Kava + Ranitidine

Ranitidine brand names: Zantac 150 EFFER, Zantac 150 GEL, Zantac 150, Zantac Geldose, Zantac, and others.

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

Kava has a moderate interaction with Ranitidine. It is unclear if kava inhibits P-glycoprotein (P-gp); research is conflicting.

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

Kava and Ranitidine

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

Moderate

P-GLYCOPROTEIN SUBSTRATES

Why this applies to Ranitidine

Ranitidine falls under P-GLYCOPROTEIN SUBSTRATES — the group Kava interacts with.

It is unclear if kava inhibits P-glycoprotein (P-gp); research is conflicting.
In vitro research shows that kava can inhibit P-gp efflux. However, a clinical study in healthy volunteers shows that taking kava standardized to provide 225 mg kavalactones daily for 14 days does not affect the pharmacokinetics of digoxin, a P-gp substrate. It is possible that the use of other P-gp substrates or higher doses of kava might still inhibit P-gp.
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 kava and ranitidine. Ranitidine is partly moved around your body by a transporter called P-glycoprotein, and in test-tube studies kava seemed to slow that transporter down. In theory, if kava blocked it, a bit more ranitidine could hang around, which might mean slightly stronger acid-lowering or a touch more of the usual side effects like headache, dizziness, or constipation.

But here's the reassuring part: this is mostly lab and animal data, and a human study with another P-glycoprotein drug (digoxin) showed no real change. So a meaningful interaction here looks unlikely. The bigger thing to keep in mind is kava's rare liver risk. If you take both, it's worth a quick chat with your pharmacist or doctor.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Weiss J, Sauer A, Frank A, Unger M. Extracts and kavalactones of Piper methysticum G. Forst (kava-kava) inhibit P-glycoprotein in vitro. Drug Metab Dispos 2005;33:1580-3. PubMed
  2. Gurley BJ, Swain A, Barone GW, et al. Effect of goldenseal (Hydrastis canadensis) and kava kava (Piper methysticum) supplementation on digoxin pharmacokinetics in humans. Drug Metab Dispos 2007;35:240-5. PubMed
  3. Asher GN, Corbett AH, Hawke RL. Common Herbal Dietary Supplement-Drug Interactions. Am Fam Physician. 2017;96(2):101-107.

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

Kava Also Interacts With Other Medications

Kava has 248 major, 576 moderate, 341 minor known drug interactions in our database — the Ranitidine one above is one of them. If you take anything else, check it against the full list below.

Major 248 Moderate 576 Minor 341 No known interaction 1,665 (incl. Ranitidine)
Taking anything else?

Check Another of Your Medications Against Kava

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

From our Q&A

Questions About Kava or Ranitidine

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

This page covers Kava only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Ranitidine page lists 74 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), St. John's Wort (major), African Wild Potato (moderate), Banderol (moderate) and Beer (moderate).

By severity: 2 major · 43 moderate · 29 minor.

From our pharmacist’s overview on the Ranitidine page

“Ranitidine (Zantac) is a heartburn and ulcer medicine gentle enough to have sold over the counter, but two of the 74 supplements and herbs on file with it earn real caution and are worth understanding first. Activated charcoal can soak up ranitidine in the gut and blunt the dose, and St.”

Reviewed by 2 · Jul 18, 2026

Open the Ranitidine interaction page

One more smart check

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

We hold 403 real supplement products containing Kava, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Kava. Your product may carry other ingredients that interact with Ranitidine too, on top of Kava — 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 Kava and Ranitidine 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 Kava
Top 25%

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

29 days ago today
Medication Ranitidine
Top 10%

#162 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 Kava

What is Kava?

Kava
  • Anxiety and stress
  • Restlessness
  • Trouble sleeping
  • Relaxation in social or cultural settings
  • Menopausal symptoms

Kava is a Pacific Island plant traditionally used to promote relaxation and ease anxiety, and some studies suggest it may help mild anxiety. However, kava has been linked to rare but serious liver damage, so it should be used with caution, avoided by people with liver problems, and only used after talking with your pharmacist or doctor.

Read the full Kava monograph & all interactions
Medication

About Ranitidine

What Is Ranitidine Used For?

Brand names: Zantac 150 EFFER, Zantac 150 GEL, Zantac 150, Zantac Geldose, Zantac, Ranit, Zantac Efferdose, Zantac 300, Zantac 300 GEL, Ranitidine injection

Ranitidine is used to treat several acid-related stomach and esophageal conditions. These include active duodenal ulcers (ulcers in the small intestine) and benign gastric ulcers (stomach ulcers), GERD (gastroesophageal reflux disease, or chronic acid reflux), erosive esophagitis (irritation and damage to the esophagus from acid), and pathological hypersecretory conditions — rare disorders where the stomach produces too much acid, such as Zollinger-Ellison syndrome and systemic mastocytosis. It is also used as maintenance therapy to keep ulcers and esophagitis from coming back after healing.

Over-the-counter products Acid Reducer and Wal-Zan tablets are specifically labeled to relieve heartburn associated with acid indigestion and sour stomach, and to prevent heartburn brought on by certain foods or beverages.

See full Ranitidine drug information
Keep checking

Other Drugs & Kava

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

248Major
576Moderate
341Minor
1,664No known interaction
248 Major 576 Moderate 341 Minor 1,664 No interaction
Major

248 interactions

Showing 60 of 248 major interactions — see all 248 on the Kava page.

Moderate

576 interactions

Showing 60 of 576 moderate interactions — see all 576 on the Kava page.

Minor

341 interactions

Showing 60 of 341 minor interactions — see all 341 on the Kava page.

No interaction 1,664 drugs checked — show the list

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

Showing the 60 most looked-up of 1,664 medications checked with no known interaction — see the full Kava list.

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

Can you take Kava with Ranitidine?
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 Kava and Ranitidine 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 Ranitidine and Kava?

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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.