Drug & supplement interaction

Calamus + Esomeprazole, Naproxen

Esomeprazole, Naproxen brand name: Vimovo.

Moderate Interaction
The bottom line Moderate

Esomeprazole, Naproxen falls into 2 drug categories that Calamus can interact with; the most serious is rated moderate. Theoretically, taking calamus with drugs metabolized by CYP3A4 might increase drug levels and potentially increase the risk of adverse effects.

Read the full interaction report
SeverityModerate
LikelihoodPossible
Interactions2
EvidenceD
What do Severity, Likelihood & Evidence mean?
Know someone taking this? Share
Interaction report

Calamus and Esomeprazole, Naproxen

These two interact in 2 distinct ways. Each one is explained separately below.

Why Are There 2 Interactions?

Calamus interacts with whole categories of medication. Esomeprazole, Naproxen falls into 2 of those categories, so it can interact with Calamus in 2 different ways. We’ve listed each one below — your overall risk is driven by the most serious of them (Moderate).

Moderate

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES

1 of 2

Why this applies to Esomeprazole, Naproxen

Esomeprazole, Naproxen falls under CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES — the group Calamus interacts with.

Theoretically, taking calamus with drugs metabolized by CYP3A4 might increase drug levels and potentially increase the risk of adverse effects.
In vitro research shows that calamus extract inhibits CYP3A4 enzyme.
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

Vimovo combines two medicines: esomeprazole (a stomach acid reducer) and naproxen (an anti-inflammatory pain reliever). The concern here is that, in lab studies only, calamus appears to slow down a liver enzyme called CYP3A4 that helps process certain drugs. If that effect held true in people, these medicines could build up a bit and lead to stronger effects, like stomach upset, heartburn, or, with naproxen especially, a higher chance of stomach irritation or bleeding.

That said, this is theoretical and based only on test-tube research, so I wouldn't lose sleep over it. The bigger issue is that calamus contains beta-asarone, which the FDA banned from foods over safety worries. Honestly, I'd skip calamus altogether, but please check with your pharmacist or doctor first.

References
  1. Pandit S, Mukherjee PK, Ponnusankar S, Venkatesh M, Srikanth N. Metabolism mediated interaction of a-asarone and Acorus calamus with CYP3A4 and CYP2D6. Fitoterapia 2011;82(3):369-74.
Minor

PROTON PUMP INHIBITORS (PPIs)

2 of 2

Esomeprazole, Naproxen also falls under PROTON PUMP INHIBITORS (PPIs).

Theoretically, taking calamus might reduce the effectiveness of PPIs.
Some research suggests that calamus lowers gastric pH.
Severity Minor 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

Vimovo is a combo pill: esomeprazole, a proton pump inhibitor that lowers stomach acid, plus naproxen, an anti-inflammatory pain reliever. The esomeprazole half is there to protect your stomach from the naproxen. There's a theory that calamus could nudge your stomach acid the wrong way and work against what the esomeprazole is trying to do. If that happened, you might notice more heartburn, indigestion, or stomach irritation from the naproxen.

I'll be honest with you: this is based on weak, anecdotal evidence, not solid human studies, so the real-world risk is probably small. The bigger concern is calamus itself, since it contains beta-asarone and is best avoided. Please run it by your pharmacist or doctor before combining them.

References
  1. Brinker F. Herb Contraindications and Drug Interactions. 2nd ed. Sandy, OR: Eclectic Medical Publications, 1998.

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

Calamus Also Interacts With Other Medications

Calamus has 1,097 moderate, 19 minor known drug interactions in our database — the Esomeprazole, Naproxen one above is among them. If you take anything else, check it against the full list below.

Taking anything else?

Check Another of Your Medications Against Calamus

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

Everything else you take

See Every Supplement That Interacts With Esomeprazole, Naproxen

This page covers Calamus only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Esomeprazole, Naproxen page lists 348 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Asarabacca (major), Beer (major), Danshen (major) and Grapefruit (major).

By severity: 9 major · 283 moderate · 56 minor.

From our pharmacist’s overview on the Esomeprazole, Naproxen page

“Bleeding risk is the thread running through nearly this whole page. Vimovo pairs naproxen, an anti-inflammatory that already makes stomach bleeding more likely, with esomeprazole on board to shield the gut, and most of the supplements flagged here could push that bleeding risk higher still.”

Reviewed by 2 · Jul 18, 2026

Open the Esomeprazole, Naproxen interaction page

One more smart check

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

We hold 71 real supplement products containing Calamus, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Calamus. Your product may carry other ingredients that interact with Esomeprazole, Naproxen too, on top of Calamus — 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 Calamus and Esomeprazole, Naproxen 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 Calamus
Steady interest

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

29 days ago today
Medication Esomeprazole, Naproxen
Steady interest

#2,098 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 Calamus

What is Calamus?

Calamus
  • Digestive upset and gas
  • Loss of appetite
  • Memory and focus (traditional)
  • Coughs and colds
  • Calming or sedative effect (traditional)

Calamus is a swamp plant with a long history in Ayurvedic and traditional Chinese medicine, mostly for digestive and nervous-system complaints. However, it contains beta-asarone, a compound linked to cancer and other toxic effects in animal studies, which is why the U.S. FDA banned it from foods. Because of these safety concerns and a lack of solid human evidence, it is generally best avoided.

Read the full Calamus monograph & all interactions
Keep checking

Other Drugs & Calamus

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

0Major
1,097Moderate
19Minor
1,713No known interaction
Moderate

1,097 interactions

Showing 60 of 1,097 moderate interactions — see all 1,097 on the Calamus page.

Minor

19 interactions

No interaction 1,713 drugs checked — show the list
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
Pharmacist Counseling Corner

Taking Calamus and Esomeprazole, Naproxen Together: Common Questions

Can you take Calamus with Esomeprazole, Naproxen?
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.
Why are there 2 interactions listed for Calamus and Esomeprazole, Naproxen?
Esomeprazole, Naproxen belongs to more than one drug category, and Calamus interacts with each of those categories a little differently. We list every one so nothing is missed — your overall risk is driven by the most serious of them.
How serious is the Calamus and Esomeprazole, Naproxen 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 Esomeprazole, Naproxen and Calamus?

Our pharmacists answer your medication & supplement questions — free.

Ask a pharmacist

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.