Drug & supplement interaction

Bismuth + Omeprazole

Omeprazole brand names: Prilosec, Zegerid, Losec.

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

Bismuth has a moderate interaction with Omeprazole. Theoretically, concomitant use of bismuth and omeprazole may increase the effects and side effects of bismuth.

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

Bismuth and Omeprazole

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

Moderate

OMEPRAZOLE (Prilosec)

Theoretically, concomitant use of bismuth and omeprazole may increase the effects and side effects of bismuth.
In humans, omeprazole increases the absorption of bismuth from tripotassium dicitrato bismuthate. The area under the concentration-time curve (AUC) and urinary excretion (Ae) of bismuth have been shown to be higher when tripotassium dicitrato bismuthate is administered with omeprazole (172 ± 158 mcg/L/hour and 1.9 ± 2.0 mg per eight hours, respectively) compared with administration alone (46 ± 33 mcg/L/hour and 0.27 ± 0.28 mg per eight hours, respectively).
Severity Moderate Likelihood Possible Evidence B

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 twist with this pairing: it's not your omeprazole (Prilosec) that builds up, it's the bismuth. By lowering stomach acid, omeprazole changes the gut environment in a way that lets more bismuth get absorbed into your body. One human study showed bismuth levels rose roughly three to four times higher when it was taken alongside omeprazole.

For occasional, short-term use of a bismuth product like Pepto-Bismol, this usually isn't a big worry. The concern is more about taking concentrated bismuth regularly for a long stretch, since higher bismuth levels over time aren't ideal. Your omeprazole keeps working normally either way. If you find yourself reaching for both often, check in with your pharmacist or doctor so they can guide the timing and duration.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Treiber, G., Walker, S., and Klotz, U. Omeprazole-induced increase in the absorption of bismuth from tripotassium dicitrato bismuthate. Clin Pharmacol Ther 1994;55(5):486-491. 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

Bismuth Also Interacts With Other Medications

Bismuth has 124 moderate known drug interactions in our database — the Omeprazole one above is one of them. If you take anything else, check it against the full list below.

Moderate 124 No known interaction 2,706 (incl. Omeprazole)
Taking anything else?

Check Another of Your Medications Against Bismuth

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

From our Q&A

Questions About Bismuth or Omeprazole

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

This page covers Bismuth only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Omeprazole page lists 174 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Grapefruit (major), St. John's Wort (major), Acacia Rigidula (moderate) and Adrafinil (moderate).

By severity: 3 major · 121 moderate · 50 minor.

From our pharmacist’s overview on the Omeprazole page

“Omeprazole (Prilosec, Zegerid, Losec) is an acid reducer for heartburn, reflux, and ulcers, and because it sits on pharmacy shelves next to the vitamins, people tend to assume it mixes safely with anything. This list argues otherwise, and it warrants genuine care.”

Reviewed by 2 · Jul 18, 2026

Open the Omeprazole interaction page

One more smart check

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

We hold 65 real supplement products containing Bismuth, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Bismuth. Your product may carry other ingredients that interact with Omeprazole too, on top of Bismuth — 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 Bismuth and Omeprazole 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 Bismuth
Top half

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

29 days ago today
Medication Omeprazole
Top 5%

#45 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 Bismuth

What is Bismuth?

  • Upset stomach and indigestion
  • Diarrhea
  • Heartburn and nausea
  • Helicobacter pylori treatment (with other drugs)
  • Traveler's diarrhea prevention

Bismuth is a metallic element used in medicine mostly as bismuth subsalicylate (the active ingredient in some well-known stomach remedies) to ease upset stomach, heartburn, nausea, and diarrhea. It is generally well tolerated for short-term use, but it can cause harmless black stools or a dark tongue, and because most products contain salicylate, it carries cautions similar to aspirin. Always follow the label and check with a pharmacist before regular use.

Read the full Bismuth monograph & all interactions
Medication

About Omeprazole

What Is Omeprazole Used For?

Brand names: Prilosec, Zegerid, Losec

Omeprazole is used to treat a range of conditions where stomach acid causes problems. These include heartburn and acid reflux (GERD), erosive esophagitis (damage to the esophagus from acid), and stomach or duodenal ulcers. It can also be used alongside antibiotics to help get rid of an H. pylori infection — a bacteria that causes ulcers.

In more serious cases, omeprazole is used to manage conditions where the stomach produces far too much acid, such as pathologic hypersecretory conditions (rare medical disorders that cause extreme acid overproduction). It is approved for adults and children one year of age and older for GERD and erosive esophagitis.

See full Omeprazole drug information
Keep checking

Other Drugs & Bismuth

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

0Major
124Moderate
0Minor
2,705No known interaction
124 Moderate 2,705 No interaction
Moderate

124 interactions

Showing 60 of 124 moderate interactions — see all 124 on the Bismuth page.

No interaction 2,705 drugs checked — show the list

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

Showing the 60 most looked-up of 2,705 medications checked with no known interaction — see the full Bismuth list.

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

Can you take Bismuth with Omeprazole?
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 Bismuth and Omeprazole 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 Omeprazole and Bismuth?

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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.