Drug & supplement interaction

Garlic + Aspirin

Aspirin brand names: Children's Aspirin, Easprin, Ecotrin, ASA, Asaphen, and others.

Moderate Interaction
The bottom line Moderate

Garlic has a moderate interaction with Aspirin. Garlic may have antiplatelet effects and may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.

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

Garlic and Aspirin

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

Moderate

ANTICOAGULANT/ANTIPLATELET DRUGS

Why this applies to Aspirin

Aspirin falls under ANTICOAGULANT/ANTIPLATELET DRUGS — the group Garlic interacts with.

Garlic may have antiplatelet effects and may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
Raw garlic and a variety of garlic extracts have antiplatelet activity and can increase prothrombin time.
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 thing about combining garlic supplements with aspirin: both can make your blood platelets a little less sticky. Aspirin already works by keeping platelets from clumping together, which is exactly why it helps with clots but also why it can cause bruising and bleeding. Concentrated garlic may nudge things in the same direction, so stacking them could mean a bit more bleeding risk, things like easy bruising, nosebleeds, or stomach upset.

I want to be honest though: this concern is theoretical, based on how garlic behaves in the lab, not proven in people taking aspirin. Garlic in your cooking is very unlikely to matter. If you take daily aspirin and want a garlic supplement, just run it by your pharmacist or doctor first.

References
  1. Rose KD, Croissant PD, Parliament CF, Levin MB. Spontaneous spinal epidural hematoma with associated platelet dysfunction from excessive garlic ingestion: a case report. Neurosurg 1990;26:880-2. PubMed
  2. Sunter WH. Warfarin and garlic. Pharm J 1991;246:722.
  3. Steiner M, Lin RS. Changes in platelet function and susceptibility of lipoproteins to oxidation associated with administration of aged garlic extract. J Cardiovasc Pharmacol 1998;31:904-8. PubMed
  4. Rahman K, Billington D. Dietary supplementation with aged garlic extract inhibits ADP-induced platelet aggregation in humans. J Nutr 2000;130:2662-5. PubMed
  5. Steiner M, Li W. Aged garlic extract, a modulator of cardiovascular risk factors: a dose-finding study on the effects of AGE on platelet functions. J Nutr 2001;131:980S-4S. PubMed
  6. Kiesewetter H, Jung F, Jung EM, et al. Effect of garlic on platelet aggregation in patients with increased risk of juvenile ischaemic attack. Eur J Clin Pharmacol 1993;45:333-6. PubMed
  7. Legnani C, Frascaro M, Guazzaloca G, et al. Effects of a dried garlic preparation on fibrinolysis and platelet aggregation in healthy subjects. Arzneimittelforschung 1993;43:119-22.
  8. Gadkari JV, Joshi VD. Effect of ingestion of raw garlic on serum cholesterol level, clotting time and fibrinolytic activity in normal subjects. J Postgrad.Med 1991;37:128-131.
  9. Woodbury A, Sniecinski R. Garlic-induced surgical bleeding: How much is too much? A Case Rep. 2016;7(12):266-269. 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

Garlic Also Interacts With Other Medications

Garlic has 988 moderate known drug interactions in our database — the Aspirin one above is one of them. If you take anything else, check it against the full list below.

Taking anything else?

Check Another of Your Medications Against Garlic

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

From our Q&A

Questions About Garlic or Aspirin

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

This page covers Garlic only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Aspirin 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 Aspirin page

“Aspirin thins the blood on purpose, and most of the 242 supplements and herbs on this page push that same effect further, so genuine care is warranted here rather than a shrug. Just over 200 of the entries can add to aspirin's antiplatelet action and raise the odds of bruising or bleeding, particularly in the stomach.”

Reviewed by 2 · Jul 18, 2026

Open the Aspirin interaction page

One more smart check

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

We hold 4,118 real supplement products containing Garlic, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Garlic. Your product may carry other ingredients that interact with Aspirin too, on top of Garlic — 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 Garlic and Aspirin 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 Garlic
Top 5%

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

29 days ago today
Medication Aspirin
Top 1%

#17 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 Garlic

What is Garlic?

Garlic
  • High blood pressure
  • High cholesterol
  • Heart health
  • Immune support and common cold
  • Antimicrobial uses

Garlic is a common food and supplement that may modestly help with blood pressure and cholesterol, though the evidence is mixed and effects are usually small. It is generally safe in food amounts, but concentrated supplements can cause stomach upset, breath and body odor, and a higher risk of bleeding. Talk with your pharmacist or doctor before taking garlic supplements, especially if you take other medicines.

Read the full Garlic monograph & all interactions
Medication

About Aspirin Rectal

What Is Aspirin Rectal Used For?

Brand names: Children's Aspirin, Easprin, Ecotrin, ASA, Asaphen, Aspirin, Gencardia, Micropirin, Angettes 75, Caprin, Nu-Seals Aspirin, Resprin, Durlaza, Cartia

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 & Garlic

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

0Major
988Moderate
0Minor
1,841No known interaction
Moderate

988 interactions

Showing 60 of 988 moderate interactions — see all 988 on the Garlic page.

No interaction 1,841 drugs checked — show the list
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

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Pharmacist Counseling Corner

Taking Garlic and Aspirin Together: Common Questions

Can you take Garlic with Aspirin?
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 Garlic and Aspirin 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.