Ibuprofen and Aspirin: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Ibuprofen
Aspirin
How we grade severity & evidence
Severity levels
- Contraindicated: These should generally not be used together.
- Major: Potentially serious — often needs a change or close monitoring.
- Moderate: Can be significant — usually manageable with monitoring.
- Minor: Usually limited clinical impact.
Evidence grades
- Established: Well documented — supported by controlled studies or strong clinical data.
- Probable: Good supporting evidence, though not definitively proven.
- Suspected: Some evidence suggests this interaction, but it is not well established.
- Possible: Limited or conflicting evidence; the interaction may occur.
- Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.
Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.
What happens
Decreased antiplatelet effect of aspirin, additive risk of bleeding, decreased renal function, and an increased risk of cardiovascular events
Interaction Deep Dive
Concurrent use of analgesic doses of aspirin with ibuprofen is generally not recommended due to an increased risk of bleeding1 and may also lead to decreased renal function 2. Due to possible increased risk of cardiovascular events due to the interference of ibuprofen with the antiplatelet effect of aspirin 3, consider use of an NSAID that does not interfere with the antiplatelet effect of aspirin, or non-NSAID analgesics, where appropriate in patients taking low-dose aspirin for cardioprotection. If concomitant use is warranted, administer immediate-release aspirin at least 2 hours 1 before or at least 8 hours after ibuprofen 4. Administer extended-release aspirin at least 2 to 4 hours before or wait 8 hours after taking ibuprofen 5.
Why it happens (mechanism)
Competition for COX-1 binding site; additive effects on hemostasis; interference with antiplatelet effects
Literature reports
4 reports — tap to read
a) Pharmacodynamic studies have demonstrated interference with the antiplatelet activity of aspirin when ibuprofen (400 mg three times daily) is administered with enteric-coated low-dose aspirin. The interaction exists even following a once-daily regimen of ibuprofen 400 mg, particularly when ibuprofen is dosed prior to aspirin. The interaction is alleviated if immediate-release low-dose aspirin is dosed at least 2 hours prior to a once-daily regimen of ibuprofen; however, this finding cannot be extended to enteric-coated low-dose aspirin 1.
b) Inhibition of platelet aggregation by aspirin was nearly completely abolished when ibuprofen was taken 2 hours before aspirin in healthy subjects in a randomized, crossover study. Subjects received aspirin 81 mg 2 hours before ibuprofen 400 mg daily for 6 days followed by a 14 day washout period, then subjects received the same drugs in reverse order. Acetaminophen, diclofenac, and rofecoxib were similarly studied and did not alter the antiplatelet effect of aspirin. Serum thromboxane B2 and platelet aggregation were inhibited at 24 hours by 99% and 98%, respectively, when aspirin was taken before ibuprofen. In contrast, when ibuprofen was taken before aspirin, serum thromboxane B2 and platelet aggregation were inhibited at 24 hours by 53% and 2%, respectively 6.
c) Concomitant therapy with ibuprofen in patients taking aspirin for cardioprotective effect increased the risk of all-cause mortality in a retrospective cohort study. The study included 7107 patients (age 27 to 100 years) discharged from the hospital with diagnoses of myocardial infarction, angina, stroke or transient ischemic attack, and peripheral vascular disease. Patients had prescriptions for aspirin alone (n=6285), aspirin plus ibuprofen (n=187), aspirin plus diclofenac (n=206), or aspirin and other NSAIDs (n=429). Aspirin doses were less than 325 mg daily, the average ibuprofen dose was 1210 mg daily, and the average diclofenac dose was 117 mg daily. Patients receiving aspirin plus ibuprofen had an increased risk of all-cause mortality and cardiovascular mortality. Patients receiving diclofenac or other NSAIDs did not have an increased risk of mortality. Potential confounders not controlled for in this study included severity of cardiovascular disease, smoking status, body mass index, and doses of individual NSAIDs 7.
d) In an unpublished study, a single ibuprofen 400 mg dose interfered with the antiplatelet activity, as measured by serum thromboxane B2 level, when administered within 30 minutes after immediate-release aspirin 81 mg. The interaction also occurred when a single dose of ibuprofen 400 mg was taken within 8 hours before aspirin dosing 4.
Common questions
Can I take Ibuprofen and Aspirin together?
Decreased antiplatelet effect of aspirin, additive risk of bleeding, decreased renal function, and an increased risk of cardiovascular events Always confirm with your pharmacist or prescriber before making any change.
How serious is the Ibuprofen and Aspirin interaction?
It is rated major. Potentially serious — often needs a change or close monitoring.
How quickly could this interaction happen?
The documented onset is "unspecified". The timing of this interaction is not well characterized.
How strong is the evidence for this interaction?
The evidence is graded "probable". Good supporting evidence, though not definitively proven.
From our Q&A
Real reader questions about these medications, each personally answered by our pharmacist:
Questions for your pharmacist
- Does my dose of Ibuprofen or Aspirin need adjusting while I take them together?
- What symptoms should prompt me to call you or my prescriber right away?
- Does the timing of my doses matter for this combination?
- Is there a safer alternative to one of these medications for me?
References (7)
- Product Information: DUEXIS(R) oral tablets, ibuprofen famotidine oral tablets. Horizon Pharma USA, Inc. (per FDA), Lake Forest, IL, 2019. DailyMed
- Product Information: CARISOPRODOL, ASPIRIN, CODEINE PHOSPHATE oral tablets, carisoprodol, aspirin, codeine phosphate oral tablets. Ingenus Pharmaceuticals LLC (per DailyMed), Orlando, FL, 2021. DailyMed
- Hohlfeld T, Saxena A, & Schror K: High on treatment platelet reactivity against aspirin by non-steroidal anti-inflammatory drugs--pharmacological mechanisms and clinical relevance. Thromb Haemost 2013; 109(5):825-833. PubMed
- US Food and Drug Administration: New Information for Healthcare Professionals Concomitant Use of Ibuprofen and Aspirin. US Food and Drug Administration. Rockville, MD. 2006.
- Product Information: DURLAZA(TM) oral extended release capsules, aspirin oral extended release capsules. New Haven Pharmaceuticals (per manufacturer), North Haven, CT, 2015. DailyMed
- Catella-Lawson F, Reilly MP, Kapoor SC, et al: Cyclooxygenase inhibitors and the antiplatelet effects of aspirin. New Engl J Med 2001; 345(25):1809-1817. PubMed
- MacDonald TM & Wei L: Effect of ibuprofen on cardioprotective effect of aspirin. Lancet 2003; 361(9357):573-574. DOI
Keep reading about Ibuprofen
Keep reading about Aspirin
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