Fish oil (EPA/DHA) and Warfarin: interaction, severity and spacing
Fish oil (EPA/DHA) and Warfarin interact because ePA and DHA displace arachidonic acid and reduce thromboxane production, which prolongs bleeding time on top of warfarin. Take them with care. Moderate risk.
The interaction in detail
| Pair | Fish oil (EPA/DHA) and Warfarin |
|---|---|
| Type | Nutrient–drug interaction |
| Severity | Moderate |
| Required spacing | None specified |
| Onset | At the time of dosing |
Mechanism
EPA and DHA displace arachidonic acid and reduce thromboxane production, which prolongs bleeding time on top of warfarin.
What to do
Doses up to 2 g combined EPA+DHA are usually tolerated; higher doses need prescriber awareness and INR check.
How to fit both into one day
Take fish oil with a fat-containing meal to improve absorption and minimise reflux. Keep combined EPA+DHA at or below 2 g on anticoagulants.
An evening dose is conventional so the INR drawn the next morning reflects a stable interval. Keep vitamin K intake consistent.
Putting Fish oil (EPA/DHA) in the midday and Warfarin in the evening satisfies the 0-hour separation without disrupting either one's absorption window.