Fish oil and medications: what to check

Fish oil has a mild, dose-related antiplatelet effect on its own — weak enough that a review of the clinical literature found no meaningful increase in surgical bleeding risk from fish oil alone. That effect becomes more relevant when fish oil is combined with a blood-thinning medication, which is the main interaction worth checking before combining the two.

Blood-thinning and antiplatelet medications

A review of the basic science and clinical trial literature on fish oil (covering 1980–2017) found it inhibits platelet-to-platelet adhesion and platelet-stimulated thrombin generation — a mild coagulopathic effect on its own. That effect is enhanced, and may become clinically noticeable, in people also taking antiplatelet drugs, and to a lesser extent in people taking factor Xa inhibitors or warfarin. Taken alone, without another anticoagulant, the same review found fish oil isn't capable of producing a clinically significant bleeding problem. If you take a prescription blood thinner or antiplatelet medication, ask your doctor or pharmacist before adding fish oil, rather than assuming either way.

Aspirin and other pain relievers

Aspirin itself is an antiplatelet drug, so the same mechanism above applies: combining regular aspirin use with fish oil is worth mentioning to a doctor, particularly if you're also taking a prescription blood thinner. We haven't found trial data on fish oil specifically alongside other common over-the-counter pain relievers.

Before surgery

Because of the antiplatelet effect, some surgeons ask patients to stop fish oil for a period before a procedure. Ask your surgeon or anesthesiologist for a specific timeline rather than guessing — this applies to any fish oil product, including Electric Tiger Omega-3, not just higher-dose or prescription forms.

Other supplements

Our softgel includes vitamin E, which is added as an antioxidant to help keep the oil from degrading in the bottle — it's a standard practice for fish oil products, not a separate active ingredient at a dose meant to add up with a vitamin E supplement you might already take. If you take a standalone vitamin E supplement at a meaningful dose, mention both to your doctor, the same as you would for any two supplements combined.

Questions people ask

Does fish oil interact with any medications?

The clearest documented interaction is with blood-thinning and antiplatelet medications — warfarin, factor Xa inhibitors, and antiplatelet drugs — where fish oil's own mild antiplatelet effect can add to theirs. Ask your doctor or pharmacist if you take any of these.

Is fish oil a blood thinner?

Not in the way a prescription blood thinner is. Fish oil has a mild, weak antiplatelet effect on its own, which a review of the clinical literature found isn't enough by itself to meaningfully raise bleeding risk. It's the combination with an actual blood-thinning medication that's worth checking with a doctor about.

Can I take fish oil with aspirin?

Both have an antiplatelet effect, so the combination is worth mentioning to your doctor, especially if you take aspirin regularly or are also on a prescription blood thinner.

Should I stop fish oil before surgery?

Ask your surgeon. Some ask patients to pause fish oil beforehand because of its mild effect on platelets; the right timeline depends on the specific procedure.

Related reading: who should not take fish oil, fish oil side effects, and how much fish oil should you take a day.