NutriStack
Fish Oil and Prasugrel, a caution.
Fish oil's omega-3 fatty acids reduce platelet thromboxane A2 generation and modestly prolong bleeding time. Added to prasugrel's potent irreversible P2Y12 inhibition, high-dose fish oil (more than 3 g/day EPA+DHA) can additively raise bleeding risk, particularly perioperatively. Prasugrel's bleeding rate is already higher than clopidogrel's.
One pair, every claim cited. The two substances, the type, the mechanism, the recommendation, and the primary literature.
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What the row says.
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At a glance
- 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. Fish oil's omega-3 fatty acids reduce platelet thromboxane A2 generation and modestly prolong bleeding time. Added to prasugrel's potent irreversible P2Y12 inhibition, high-dose fish oil (more than 3 g/day EPA+DHA) can additively raise bleeding risk, particularly perioperatively. Prasugrel's bleeding rate is already higher than clopidogrel's.
Mechanism. EPA and DHA displace arachidonic acid in platelet membranes, reducing thromboxane A2 generation and platelet aggregation. This adds to prasugrel's irreversible blockade of platelet P2Y12 receptors.
Recommendation. Keep fish oil dose modest (≤2 g/day combined EPA+DHA) on prasugrel and keep the dose constant. Stop fish oil at least 7 days before any planned surgery.
Sources (2)
- Watson PD, Joy PS, Nkonde C, Hessen SE, Karalis DG. Comparison of bleeding complications with omega-3 fatty acids + aspirin + clopidogrel--versus--aspirin + clopidogrel in patients with cardiovascular disease. Am J Cardiol. 2009;104(8):1052-4. PMID 19801023
- Buckley MS, Goff AD, Knapp WE. Fish oil interaction with warfarin. Ann Pharmacother. 2004;38(1):50-2. PMID 14742793
Stack Score
How this pair moves the number.
Effect on the composite score
If both Fish Oil and Prasugrel 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.
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