Drug & supplement interaction

Bismuth + Aspirin, Dipyridamole

Aspirin, Dipyridamole brand names: Aggrenox, Asasantin Retard.

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

Aspirin, Dipyridamole falls into 2 drug categories that Bismuth can interact with; the most serious is rated moderate. Theoretically, use of bismuth subgallate or other bismuth salts might reduce the effects of anticoagulant/antiplatelet drugs.

Read the full interaction report
SeverityModerate
LikelihoodPossible
Interactions2
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Bismuth and Aspirin, Dipyridamole

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

Why Are There 2 Interactions?

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

Moderate

ANTICOAGULANT/ANTIPLATELET DRUGS

1 of 2

Why this applies to Aspirin, Dipyridamole

Aspirin, Dipyridamole falls under ANTICOAGULANT/ANTIPLATELET DRUGS — the group Bismuth interacts with.

Theoretically, use of bismuth subgallate or other bismuth salts might reduce the effects of anticoagulant/antiplatelet drugs.
In humans, bismuth subgallate activates factor XII and accelerates the coagulation cascade.
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

Aggrenox combines aspirin with dipyridamole, and it's prescribed to keep platelets from clumping so you're less likely to form a clot, often after a stroke or mini-stroke. Neither piece is a prodrug here, so the concern works in one direction: bismuth (like the kind in some stomach remedies) might slightly nudge your blood toward clotting, which could blunt how well Aggrenox does its job.

I want to be honest that this is a theoretical worry based on how bismuth behaves in the body, not something we see causing problems in real life. An occasional dose for an upset stomach is very unlikely to matter. Still, since these salicylate products also act like aspirin, it's worth a quick chat with your pharmacist before using bismuth regularly.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Callanan, V., Curran, A. J., Smyth, D. A., and Gormley, P. K. The influence of bismuth subgallate and adrenaline paste upon operating time and operative blood loss in tonsillectomy. J Laryngol Otol 1995;109(3):206-208. PubMed
Moderate

ASPIRIN

2 of 2
Theoretically, bismuth subsalicylate might have an additive effect with other salicylate-containing drugs.
Dietary supplements often contain bismuth in the form of bismuth subsalicylate. In humans, oral bismuth subsalicylate is hydrolyzed in the stomach to form salicylate and bismuth oxychloride.
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 is the thing worth knowing: that popular pink stomach remedy is bismuth subsalicylate, and once it hits your stomach it breaks down into salicylate, which is the same family as the aspirin already inside your Aggrenox. So you would essentially be stacking aspirin on top of aspirin. This is a theoretical concern based on how the chemistry works, not something proven to cause harm in most people, but it is reasonable to keep in mind.

If your total salicylate load climbs, you may notice more stomach upset, easier bruising, or bleeding, and sometimes ringing in the ears. Occasional, label-dose use is usually low risk, but regular use is worth a quick chat with your pharmacist or doctor first.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Mishkin, S. Intriguing gastrointestinal properties of bismuth: a folk remedy brought into the realm of clinical and investigative medicine. Can J Gastroenterol 1998;12(8):569-570. 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 Aspirin, Dipyridamole one above is among them. If you take anything else, check it against the full list below.

Moderate 124 No known interaction 2,706 (incl. Aspirin, Dipyridamole)
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.

Everything else you take

See Every Supplement That Interacts With Aspirin, Dipyridamole

This page covers Bismuth only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Aspirin, Dipyridamole page lists 243 supplements it has a documented interaction with, worst first, each one explained.

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

By severity: 8 major · 206 moderate · 29 minor.

From our pharmacist’s overview on the Aspirin, Dipyridamole page

“Aspirin with dipyridamole (Aggrenox) keeps platelets from clumping to prevent a second stroke, so it should be no surprise that the great bulk of this page is about bleeding. Most listed supplements can thin the blood further, and the risk reaches into ordinary life: beer and wine both carry major ratings because alcohol alongside aspi…”

Reviewed by 2 · Jul 18, 2026

Open the Aspirin, Dipyridamole 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 Aspirin, Dipyridamole 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 Aspirin, Dipyridamole 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

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

29 days ago today
Medication Aspirin, Dipyridamole
Steady interest

#1,719 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
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 Aspirin, Dipyridamole, 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 Aspirin, Dipyridamole supplement interactions › Every supplement checked against Aspirin, Dipyridamole, ranked by severity 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 Aspirin, Dipyridamole Together: Common Questions

Can you take Bismuth with Aspirin, Dipyridamole?
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 Bismuth and Aspirin, Dipyridamole?
Aspirin, Dipyridamole belongs to more than one drug category, and Bismuth 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 Bismuth and Aspirin, Dipyridamole 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

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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.