Drug & supplement interaction

Bismuth + Acetylsalicylic acid

Acetylsalicylic acid brand name: Entrophen.

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

Acetylsalicylic acid 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?
Know someone taking this? Share
Facebook Post Reddit Email
On this page
Interaction report

Bismuth and Acetylsalicylic acid

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. Acetylsalicylic acid 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 Acetylsalicylic acid

Acetylsalicylic acid 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

Here's the gist for combining bismuth (the salicylate found in stomach remedies) with your aspirin. One of aspirin's jobs is to keep platelets from clumping, which is why it's used as a blood thinner. On paper, bismuth salts may nudge your clotting system in the opposite direction by switching on a clotting factor. In theory, that could slightly blunt aspirin's clot-preventing effect.

I want to be honest though: this is a theoretical concern based on how these work, not something well documented in real patients. It's also worth knowing that bismuth products usually contain salicylate themselves, so stacking them could add up. Run it by your pharmacist or doctor before using both regularly, and don't change your aspirin on your own.

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

Acetylsalicylic acid also falls under ASPIRIN.

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's the simple version: those familiar pink stomach remedies contain bismuth subsalicylate. Once it hits your stomach, it breaks down and releases salicylate, which is basically the same family of compound as the aspirin in Entrophen. So taking both at once means you're stacking salicylate on top of salicylate.

This concern is theoretical, based on how the two work rather than proven cases, but it makes sense. Doubling up could nudge you toward salicylate-type side effects like ringing in the ears, stomach upset or irritation, and a higher bleeding tendency. A single dose for an occasional upset stomach is usually minor, but regular or higher use of both deserves a quick check 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 Acetylsalicylic acid 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. Acetylsalicylic acid)
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 Acetylsalicylic acid

This page covers Bismuth only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Acetylsalicylic acid page lists 242 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 Piracetam (major).

By severity: 7 major · 206 moderate · 29 minor.

From our pharmacist’s overview on the Acetylsalicylic acid page

“Acetylsalicylic acid (aspirin, sold as Entrophen) thins the blood by design, which is exactly why this page earns real vigilance rather than a quick skim. Of the 242 supplement and herbal ingredients on file, more than 200 can add to that blood-thinning effect and raise the chance of bruising or bleeding, especially in the stomach.”

Reviewed by 2 · Jul 18, 2026

Open the Acetylsalicylic acid 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 Acetylsalicylic acid 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 Acetylsalicylic acid 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

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

29 days ago today
Medication Acetylsalicylic acid
Top 5%

#100 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 Aspirin Rectal

What Is Aspirin Rectal Used For?

Brand name: Entrophen

Aspirin rectal suppositories are used to relieve pain and reduce fever in adults. They offer an alternative route for people who may have difficulty taking aspirin by mouth.

Children under 12 should not use this product without first consulting a physician.

See full Aspirin Rectal 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 Acetylsalicylic acid, 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 Acetylsalicylic acid supplement interactions › Every supplement checked against Acetylsalicylic acid, ranked by severity Aspirin Rectal 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 Acetylsalicylic acid Together: Common Questions

Can you take Bismuth with Acetylsalicylic acid?
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 Acetylsalicylic acid?
Acetylsalicylic acid 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 Acetylsalicylic acid 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 Acetylsalicylic acid and Bismuth?

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.