NutriStack
Clopidogrel and Garlic Extract, a caution.
Garlic supplements inhibit platelet aggregation and have been studied head-to-head with clopidogrel. Combined with clopidogrel's irreversible P2Y12 inhibition, garlic stacks antiplatelet activity and can increase bleeding risk, particularly perioperatively.
One pair, every claim cited. The two substances, the type, the mechanism, the recommendation, and the primary literature.
Same shape as the other 1,729 pairs in the public database.
From the interaction database
What the row says.
Every entry follows the same shape: what is happening, the mechanism, the recommendation, and the primary literature.
At a glance
- Substances
- Clopidogrel and Garlic Extract
- Pair type
- Caution
- Evidence (highest tier)
- Emerging
- Source citations
- 2 sources
- Stack Score effect
- −5 to your Stack Score (per scored caution row).
- Scope
- Supplement × Prescription
- Last verified
- May 30, 2026
Caution · Emerging evidence
Caution
What is happening. Garlic supplements inhibit platelet aggregation and have been studied head-to-head with clopidogrel. Combined with clopidogrel's irreversible P2Y12 inhibition, garlic stacks antiplatelet activity and can increase bleeding risk, particularly perioperatively.
Mechanism. Allicin and related thiosulfinates inhibit platelet COX activity and thromboxane synthesis, modify platelet membrane properties, and reduce calcium signalling. These add to clopidogrel's blockade of ADP-mediated platelet activation via P2Y12.
Recommendation. Avoid concentrated garlic supplements on clopidogrel. Cooking with garlic is fine. Stop garlic supplements at least 7 days before any planned surgery.
Sources (2)
- Mousa AS. Comparison of antiplatelet activity of garlic tablets with cardio-protective dose of aspirin in healthy volunteers: a randomized clinical trial. Avicenna J Phytomed. 2016;6(5):556-561. PMID 27761425
- Heck AM, DeWitt BA, Lukes AL. Potential interactions between alternative therapies and warfarin. Am J Health Syst Pharm. 2000;57(13):1221-7. PMID 10902065
Stack Score
How this pair moves the number.
Effect on the composite score
If both Clopidogrel and Garlic Extract are in the same stack, this pair applies −5 to your Stack Score (per scored caution row).
The full algorithm, the clamping rules, and four worked stacks are documented at /methodology/stack-score.
Check your full routine
One pair was the worked example. NutriStack runs every pair in your stack at once.
Drop in your supplements and prescriptions and the public database surfaces every interaction, synergy, timing rule, and contraindication, every one linked to its primary source.