Drug & supplement interaction

Coffee + Aspirin, Caffeine

Aspirin, Caffeine brand name: Anacin.

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

Aspirin, Caffeine falls into 2 drug categories that Coffee can interact with; the most serious is rated moderate. Theoretically, coffee may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.

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

Coffee and Aspirin, Caffeine

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

Why Are There 2 Interactions?

Coffee interacts with whole categories of medication. Aspirin, Caffeine falls into 2 of those categories, so it can interact with Coffee 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, Caffeine

Aspirin, Caffeine falls under ANTICOAGULANT/ANTIPLATELET DRUGS — the group Coffee interacts with.

Theoretically, coffee may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
Coffee contains caffeine. Caffeine is reported to have antiplatelet activity. Theoretically, the caffeine in coffee might increase the risk of bleeding when used concomitantly with these agents. However, this interaction has not been reported in humans. There is some evidence that caffeinated coffee might increase the fibrinolytic activity in blood.
Severity Moderate Likelihood Unlikely Evidence D

Interaction has been demonstrated in animal or in lab research but has been shown not to occur in humans..

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's a fun twist: the medicine you're asking about, Anacin, already contains caffeine right alongside the aspirin. So drinking coffee on top of it simply stacks more caffeine into your day. On the bleeding side, the aspirin is the player that matters most, since it thins your blood and reduces how well platelets clump together. Coffee's own caffeine is thought to have a mild antiplatelet effect too, so in theory the two could nudge bleeding risk up a bit.

Honestly, this is a theoretical concern from lab work, not something proven in real people, so I wouldn't lose sleep over a normal cup or two. Watch for easy bruising, nosebleeds, or stomach upset, and check with your pharmacist if you take aspirin daily.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Ali M, Afzal M. A potent inhibitor of thrombin stimulated platelet thromboxane formation from unprocessed tea. Prostaglandins Leukot Med 1987;27:9-13. PubMed
  2. Ardlie NG, Glew G, Schultz BG, Schwartz CJ. Inhibition and reversal of platelet aggregation by methyl xanthines. Thromb Diath Haemorrh 1967;18:670-3. DOI
  3. Samarrae WA, Truswell AS. Short-term effect of coffee on blood fibrinolytic activity in healthy adults. Atherosclerosis 1977;26:255-60. PubMed
Moderate

STIMULANT DRUGS

2 of 2

Aspirin, Caffeine also falls under STIMULANT DRUGS.

Theoretically, concomitant use might increase stimulant adverse effects.
Coffee contains caffeine. Due to the central nervous system (CNS) stimulant effects of caffeine, concomitant use with stimulant drugs can increase the risk of adverse effects.
Severity Moderate Likelihood Probable Evidence C

Interaction 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..

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's the simple version: this product (Anacin) already contains caffeine right alongside the aspirin. So when you drink coffee on top of it, you're really just stacking caffeine on caffeine. There's no clever metabolism trick happening here, you're simply adding more of the same stimulant.

What that can feel like is the usual too-much-caffeine stuff: feeling jittery or shaky, a racing or pounding heart, trouble sleeping, and sometimes an upset or jittery stomach (and aspirin can already be hard on the stomach). This is mostly common-sense caution based on expert opinion, not a dangerous reaction. If you're sensitive to caffeine or notice your heart fluttering, ease up on the coffee and check with your pharmacist about how much is okay for you.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Institute of Medicine. Caffeine for the Sustainment of Mental Task Performance: Formulations for Military Operations. Washington, DC: National Academy Press, 2001. Available at: http://books.nap.edu/books/0309082587/html/index.html. DOI

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

Coffee Also Interacts With Other Medications

Coffee has 8 major, 466 moderate, 116 minor known drug interactions in our database — the Aspirin, Caffeine one above is among them. If you take anything else, check it against the full list below.

Major 8 Moderate 466 Minor 116 No known interaction 2,240 (incl. Aspirin, Caffeine)
Taking anything else?

Check Another of Your Medications Against Coffee

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

Everything else you take

See Every Supplement That Interacts With Aspirin, Caffeine

This page covers Coffee only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Aspirin, Caffeine page lists 347 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 Ephedra (major).

By severity: 13 major · 285 moderate · 49 minor.

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

“Anacin combines aspirin with caffeine, so supplements can hit it from two directions, and a few of the 347 on this list deserve real respect. The biggest group, over 200 ingredients, can raise bleeding risk on top of aspirin's blood-thinning effect; beer and wine carry major ratings because alcohol plus an aspirin-type drug makes stoma…”

Reviewed by 2 · Jul 18, 2026

Open the Aspirin, Caffeine interaction page

One more smart check

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

We hold 716 real supplement products containing Coffee, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Coffee. Your product may carry other ingredients that interact with Aspirin, Caffeine too, on top of Coffee — 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 Coffee and Aspirin, Caffeine 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 Coffee
Top 5%

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

29 days ago today
Medication Aspirin, Caffeine
Top 25%

#557 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 Coffee

What is Coffee?

  • Alertness and reducing fatigue
  • Mental focus and concentration
  • Athletic performance
  • Headache relief
  • Weight management

Coffee is a widely consumed beverage made from roasted coffee beans, valued mainly for its caffeine, which boosts alertness and energy. For most healthy adults, moderate coffee intake is generally safe and may have some health benefits, but too much can cause jitteriness, poor sleep, and a faster heartbeat. People who are pregnant, breastfeeding, or sensitive to caffeine should limit their intake and check with a doctor or pharmacist.

Read the full Coffee monograph & all interactions
Keep checking

Other Drugs & Coffee

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

8Major
466Moderate
116Minor
2,239No known interaction
8 Major 466 Moderate 116 Minor 2,239 No interaction
Major

8 interactions

Moderate

466 interactions

Showing 60 of 466 moderate interactions — see all 466 on the Coffee page.

Minor

116 interactions

Showing 60 of 116 minor interactions — see all 116 on the Coffee page.

No interaction 2,239 drugs checked — show the list

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

Showing the 60 most looked-up of 2,239 medications checked with no known interaction — see the full Coffee list.

See the full Coffee interactions page
See every supplement checked against Aspirin, Caffeine, 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
Coffee monograph › Uses, safety, and every drug interaction in one place Aspirin, Caffeine supplement interactions › Every supplement checked against Aspirin, Caffeine, 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 Coffee and Aspirin, Caffeine Together: Common Questions

Can you take Coffee with Aspirin, Caffeine?
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 Coffee and Aspirin, Caffeine?
Aspirin, Caffeine belongs to more than one drug category, and Coffee 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 Coffee and Aspirin, Caffeine 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.