Fish Oil Bleeding Risk

SUMMARY: Fish Oil does not appear to increase bleeding risk even when combined with aspirin or warfarin. Research does not appear to support this concern.

There are dozens of reasons to take fish oil pills.

But you also hear of a couple of reasons why you shouldn’t.

Fish oil bleeding risk is one of those reasons.

So does fish oil increase bleeding risk?

This is not an old wives tale. Eskimos bleed more than the rest of us. And that’s because they eat an average of 13,700 mg of Omega-3 per day.

‘Is that a lot?’ you ask.

Yes, it’s a whole heckuva lot. 13,700 mg of Omega-3 is equivalent to 46 regular strength fish oil pills a day. Or 13 OmegaVia pills every day.

If you consume THAT MUCH Omega-3 every day for months, your risk for bleeding may increase. And you might also notice a slight increase in nose bleeds and a slight increase in the time it takes for blood to clot.

No one in America or anywhere else for that matter, eats 13,700 mg of Omega-3 per day.

So what about fish oil bleeding risk from everyday, regular fish oil dosage?

Research shows that fish oil bleeding risk not a concern.

This is not my opinion. See below.

Here are the facts and quotations from scientists and universities:

Fish Oil Bleeding Risks
My alma mater, Purdue University is home to the Omega-3 Learning Center.

“A review of numerous studies in which patients were supplemented with omega-3 fatty acids found no clinically significant risk of bleeding.

“Also, there was no increased risk of clinically significant blood loss during delivery when pregnant women were supplemented with 2.7 grams/day of omega-3 fatty acids”

“A small study of patients on Warfarin, an anti-coagulant that is routinely monitored with blood testing, plus 3-6 grams/day of a supplement containing omega-3 fatty acids found no increase in bleeding time over a 4-week treatment period”


Fish Oil Bleeding Risks

Researchers from the Division of Cardiology at Drexel University College of Medicine say that fish oil bleeding risk is not high even if it is combined with aspirin and Plavix, an anti-clotting drug used to prevent strokes.

“High-dose fish oil is safe in combination with aspirin and clopidogrel (Plavix) and does not increase the risk of bleeding.”

Source: 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. American Journal of Cardiology 2009 Oct 15;104(8):1052-4.

Fish Oil Bleeding Risk

Johns Hopkins Ciccarone Center for the Prevention of Heart Disease published a paper in May 2010 that said “an increased risk of bleeding was not observed.”

Source: Defilippis AP, Blaha MJ, Jacobson TA. Omega-3 Fatty acids for cardiovascular disease prevention. Current Treatment Options in Cardiovascular Medicine 2010 Aug;12(4):365-80.

Fish Oil Bleeding Risk
Dr. Bill Harris from the Sanford School of Medicine at University of South Dakota says:

“Omega-3 fatty acid ethyl esters have well-known triglyceride-lowering properties and were shown over 30 years ago to inhibit platelet function.

With the recent US Food and Drug Administration (FDA) approval of these agents for treating severe triglyceride elevations, concerns about excess bleeding naturally arise.

However, an objective assessment of the evidence for clinically significant bleeding reveals that such concerns are unfounded.

As such, the benefits of triglyceride lowering with omega-3 fatty acids more than outweigh any theoretical risks for increased bleeding.”

Source: Harris WS. Expert opinion: omega-3 fatty acids and bleeding-cause for concern? American Journal of Cardiology 2007 Mar 19;99(6A):44C-46C.

Louisville Metabolic and Atherosclerosis Research Center

Fish Oil Bleeding Risk

“It has been suggested that the potential antithrombotic effect of fish oils may theoretically increase the risk for bleeding, which may be a safety concern for individual patients.

However, clinical trial evidence has not supported increased bleeding with omega-3 fatty acid intake, even when combined with other agents that might also increase bleeding (such as aspirin and warfarin).”

Source: Bays HE. Safety considerations with omega-3 fatty acid therapy. American Journal of Cardiology 2007 Mar 19;99(6A):35C-43C.

Fish Oil Bleeding Risk

In 2004, the US Dept. of Health and Human Services Agency for Healthcare Research and Quality (Whew! That’s a long name that only an agency of the government could have.) reviewed 148 different clinical studies with over 20,000 patients for signs of increased bleeding

They found that 6.6% of people taking fish oil complained about stomach distress and other fish oil side effects, but they did not notice an increased fish oil bleeding risk.

So the Feds and the scientists agree that fish oil bleeding risk is very low.

To put my money where my mouth is, my wife took 4000 mg of Omega-3 every day during her pregnancy right up until and after C-section delivery.


This website is for your education and general health information only. The ideas, opinions and suggestions contained on this website are not to be used as a substitute for medical advice, diagnosis or treatment from your doctor for any health condition or problem. Users of this website should not rely on information provided on this website for their own health problems. Any questions regarding your own health should be addressed to your own physician. Please do not start or stop any medications without consulting with your doctor. We neither encourage you to do so, nor can we be held responsible for the fall out of failing to seek the counsel of a medical health practitioner.

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Vin Kutty
Vin Kutty, MS, is co-founder of Innovix Pharma. He is a nutritionist and Omega-3 expert with 20 years of experience.


Join the Conversation

  1. Hi Vin,

    You expounded about the repeated warning of hemorrhagic stroke on medical websites (always lacking more information and quoting each other) a bit above, but something is not clear to me. I don’t see how fish oil would *cause* a hemorrhagic stroke – wouldn’t it simply make an already existing aneurysm/bleeding stroke worse, if it did anything? Or am I missing something?

    Also, wouldn’t there be other symptoms, such as excess bruising, nosebleeds, cuts that bleed for prolonged periods, etc. if you were really at higher risk for something like this?

    I currently take ~2g of fish oil a day, plus modest to low amounts of other supplements such as garlic, grape seed extract, CoQ10, quercetin, cayenne, ginger, mushroom complex (reishi, maitake, shiitake), cinnamon, pineapple, and celery seed to help with blood pressure and general well-being. Sometimes I worry I might be thinning my blood too much, but I don’t have any excess bruising or apparent bleeding (ie. nosebleeds), and I think the fish oil and supplements have been of benefit to me in other areas (dry eye, blood pressure, and cholesterol, to name a few).

    My doctor reviewed my supplements and didn’t seem to be concerned. She even indicated I could add aspirin or up my fish oil to 4g (the prescription dose), though I’d rather stick to the 2g for now and stay away from aspirin at the age of 34 and with the other whole food supplements I take.

    I sometimes wonder if discussing blood clotting tests with my doctor is warranted, but with no symptoms and feeling pretty good, I’m not sure if that’s a necessary precaution or not.

    Sorry for the length of my comments; your thoughts would certainly be appreciated, and I really appreciate all the great info on your blog!

    • Hi Shaun – I have not seen any compelling evidence that proves Omega-3, even at high doses, causes hemorrhagic stroke. There is some observational evidence in Inuit populations that consume 12 grams of Omega-3 per day that it may cause increased nosebleeds among children…but no one knows if that was because of the high Omega-3 consumption or because of the heavy metals consumed with eating a diet high in large marine mammals.

      I agree with your doctor that a baby aspirin with your Omega-3 is a good idea – the aspirin helps increase the potency of downstream anti-inflammatory compounds. Some of this is based on proprietary data and conversations with researchers who’re working with this combo. I take a baby aspirin with my Omegas.

      Suggestion: you supplement combo sounds like a delicious meal – so why not just eat all those foods instead of supplementing?

  2. Hi Vin,

    Thanks much for the feedback! Good to know not to worry re hemorrhage, etc.

    I’ll think about the baby aspirin. I’m 34, and my chief concern with starting aspirin so early (as I do believe it is a good, fairly safe drug) is risk of gastrointestinal bleeding/cerebral microbleeds and also some studies seem to show slight macular degeneration risk. I’d prefer to stick with natural supplements with similar properties until after 50 as long as I don’t have any actual signs of heart disease… But I will think about it some more and discuss with my doctor when I see her next.

    I saw one comment on here that you weren’t a fan of phytosterols; I was curious, if you care to elaborate and if you still feel they’re unwarranted as I currently get 800mg of those as well.

    As far as meals, I do eat a wide variety of foods, including fruits, vegetables, herbs, and spices, but my eating pattern varies a good bit from day to day (I try to make it more healthy than not, but I do have less-than-optimal meals from time to time). I use the small amounts of all these things in supplements to make sure I get at least a little bit of everything everyday. (None of these are megadoses…garlic, as suggested by my doctor, is the largest at 1100 mg, with everything else quite a bit less and most well under 500mg and some <100).

    Thanks again for the information and your amazing blog.

    • Hi Shaun – my thoughts on phytosterols have only grown stronger since. Two reasons why: I don’t think cholesterol is meant to be beaten into submission. If your lipids are off, talk to your doctor and get aggressive. In such cases, phytosterols won’t budge the needle much anyway. The second reason is that I’m not convinced of the safety of phytosterols for everyone. Esterified sterols reduce cholesterol but supplement industry does not know or monitor whether raw materials are esterified. Most supplements don’t label this fact and virtually all of them import it from China at a low, low price. And a bonus reason: the poor folks with the Apo E4 genetic pattern who already have enough to deal with, metabolize sterols dangerously. This could be 15 or 20% of the population.

  3. Thanks, Vin. I’ve seen that argument re cholesterol (I also like Chris Kresser’s work, which I believe is where I found your blog actually). I’m not 100% paleo, but I have incorporated some aspects into my life, for sure.

    I will reconsider my phytosterol usage. Thanks for the info. Your previous fish oil recommendations have been very helpful as well!

  4. Dear Vin
    Do you have a url for the 2004 Dept. of Health study you cite? I am finding knee-jerk warnings against my current trio – low-dose aspirin, Clop and fish oil – on web sites informed more, I suspect, by health insurance caveats than peer-reviewed research. BTW – I thank God every day for our Oz Medicare/Medibank systems.

  5. Dear Vin
    Thank you for responding and the 2004 Dept. of Health study url. re cholesterol: you write ” I don’t think cholesterol is meant to be beaten into submission” yet advise the writer to “talk to your doctor and get aggressive”? Is Lipitor macho enough – complete with sore leg muscles?
    Thanks again. I do appreciate you taking the trouble to answer our whines.

    • I wish things were more black and white, Brian 🙂 You’ve just discovered bipolarity and nuances in my off-the-cuff remarks on cholesterol. I’m surprised no one else has brought this up yet. Once you start talking about cholesterol, it’s all nuance and shades of grey. You need to get ‘aggressive’ if you have dyslipidemia…but whose definition of dyslipidemia or ‘normal’ are you going to follow? That of the pharma companies who make statins? Lipidologists? My opinion? I’d go with lipidologists. Pharma companies and doctors who take their advice beat cholesterol down ‘into submission’ once total cholesterol even approaches 200. People have signed up for this en masse because of its simplicity. But things aren’t so simple. Total cholesterol is a combination of numbers both ‘good’ and ‘bad.’ There are several causes for dyslipidemia and few of them, unfortunately, require pharmaceutical intervention. Most, fortunately, can be managed with diet and exercise. But lifestyle options are bitter pills, so to speak.

      I have absolutely no idea if Lipitor is right for you. I am neither authorized nor qualified to dispense individual medical advice. Although your leg soreness does not sound like fun. Have you tried CoQ10 at 100 mg two or three times a day?
      More here:

  6. Hi Vin. My mom had a ministroke (TIA). They gave her blood thinners and she then bled in the brain. This happened 11 days ago. They did brain surgery and she was responsive the day after but not much since then. She is 72 yrs old and very healthy. Woud omega 3 help her? I get concerned she might bleed again if they give it to her but im finding that bleeding in the brain from omega 3 doesnt happen. What are your thoughts?

    • Hi Dean – given the complexity of the situation (and that I’m neither qualified nor authorized to give out medical advice), you should consult with her doctors. There may be several factors at play here. Omega-3 may help some of them but, again, this needs to be discussed with the physicians.

  7. All I can tell you about bleeding is this. It does not matter what time of the year or if I am in a humid or dry environment. Within 3 days of supplementing ANY fish oil… just a capsule a day and I will start to get nosebleeds.

    • When I start taking fish oil as I do every few months then I too start having nose bleeds every few days. I just live with it.

      • Hi Robert – have you tried supplementing with just DHA Omega-3? Sometimes people have less of an issue with it.

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