Drug interactions
Fish oil + Warfarin
Severity: Moderate
Fish oil and Warfarin: moderate interaction.
Last updated
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Summary
Omega-3 fatty acids have mild antiplatelet effects and may modestly increase bleeding tendency. Most studies at usual doses show little effect on INR, but high doses may add to bleeding risk with warfarin.
What this interaction means in plain words
Fish oil and Warfarin can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Fish oil belongs to Gastrointestinal Tract; Warfarin belongs to Cardiovascular.
Why it happens
Mild additive antihemostatic effect from reduced platelet aggregation; no consistent effect on warfarin pharmacokinetics.
What to do
Monitor INR and signs of bleeding when starting or changing high-dose fish oil. Keep intake consistent.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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Other interactions of Fish oil
- Antithrombin alfa + Fish oil Moderate
- Antithrombin iii + Fish oil Moderate
- Aspirin / citric acid / sodium bicarbonate + Fish oil Moderate
- Aspirin + Fish oil Moderate
- Betrixaban + Fish oil Moderate
- Bivalirudin + Fish oil Moderate
Other interactions of Warfarin
- Defibrotide + Warfarin Contraindicated
- Ketorolac + Warfarin Contraindicated
- Abciximab + Warfarin Major
- Acetylsalicylic acid + Warfarin Major
- Adagrasib + Warfarin Major
- Amiodarone + Warfarin Major
Frequently asked questions
Can I take Fish oil with Warfarin?
MediHelp rates the interaction as moderate. Fish oil and Warfarin can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Omega-3 fatty acids have mild antiplatelet effects and may modestly increase bleeding tendency. Most studies at usual doses show little effect on INR, but high doses may add to bleeding risk with warfarin.
How serious is the interaction between Fish oil and Warfarin?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor INR and signs of bleeding when starting or changing high-dose fish oil. Keep intake consistent.
What other medicines interact with Fish oil?
MediHelp also lists interactions of Fish oil with, for example, Antithrombin alfa, Antithrombin iii, Aspirin / citric acid / sodium bicarbonate. The full list is on the Fish oil page.
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