Fish Oil and Bleeding: Do the Risks Outweigh the Benefits?
Key takeaways:
Fish oil provides omega-3 fatty acids that support heart, brain, and eye health. It can also help prevent blood clots, but high doses of fish oil may raise your risk of bleeding.
Fish oil and bleeding is typically only a concern with doses over 5 g per day. But the risk may be higher if you take it with other medications that raise your bleeding risk.
Fish oil supplements aren’t recommended for most people without a healthcare professional’s recommendation. It’s better to meet your omega-3 needs through your diet.
Fish oil is just one type of omega-3 supplement, and not all products are created equal — look for third-party tested options with clear ingredient and dosage information.
Table of contents
Fish oil is one of the most popular supplements on the market. The omega-3 fatty acids in fish oil help support heart health and reduce inflammation. But it can also have blood-thinning effects. This isn’t always a bad thing, but it does raise important questions about safety, especially if you’re taking certain medications or preparing for surgery.
In this article, we’ll take a closer look at fish oil and bleeding risk to help you make an informed decision about this popular supplement.
1. How does fish oil work?
Fish oil provides your body with omega-3 fatty acids — mainly EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid). Omega-3s are healthy fats that your body can’t make on its own. They can help reduce inflammation and lower triglyceride levels (a type of unhealthy fat in your blood). Omega-3s also support brain, heart, and eye health.
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Fish oil can also affect your platelets (blood cells that help form blood clots). They reduce how easily these blood cells clump together, which can help lower your risk of blood clots. This is generally considered a benefit of fish oil. But it also means your blood may take a little longer to clot if you get a cut or bruise — especially if you’re also taking other medications or supplements that affect clotting.
2. Does fish oil increase your risk of bleeding?
Yes, high doses of fish oil (more than 2 g per day) can increase your bleeding risk. As mentioned, higher levels of fish oil can make it harder for blood clots to form. This can raise the risk of unwanted bleeding.
Your bleeding risk may be higher if you take blood thinners or other medications that make bleeding more likely. These include:
Nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen (Advil, Motrin)
Selective serotonin reuptake inhibitors (SSRIs), such as sertraline (Zoloft)
Antiplatelet medications, such as clopidogrel (Plavix)
Anticoagulants, such as apixaban (Eliquis)
Other supplements, such as gingko biloba
The increased risk of bleeding caused by fish oil may also be a concern if you’re having any form of surgery. It could lead to unwanted blood loss and other complications.
Keep in mind that the amount of omega-3s needed to raise your bleeding risk is more than the recommended daily dose (250 mg to 500 mg daily for most people). So it shouldn’t be an issue in most cases. But it’s still a good idea to talk to your healthcare team before adding a fish oil supplement to your regimen. They can help determine if they’re a safe option for you based on your health history and other medications you’re taking.
3. Are fish oil and omega-3 supplements the same thing?
Not exactly. Fish oil is one natural source of omega-3 fatty acids. Fish oil supplements are typically made from fatty fish such as salmon and sardines.
Eating fish vs. fish oil supplements: Find out why it’s best to try and get omega-3s from your diet if possible.
Non-fish omega-3 sources: Learn the best ways to get omega-3s if you don’t eat fish.
Different types of omega fatty acids: Explore the differences between omega-3, omega-6, and omega-9 fatty acids, and their benefits.
But omega-3 supplements may come from sources other than fatty fish, such as:
Krill oil, which comes from tiny crustaceans rich in EPA and DHA
Microalgal oil, a vegan-friendly option made from algae
Other plant-based sources, such as flaxseed oil, chia seeds, and walnuts. These also contain another type of omega-3 called alpha-linolenic acid (ALA)
4. Is it safe to take fish oil every day?
It depends. Most experts recommend getting omega-3s from your diet over taking supplements whenever possible. It’s best to only take a fish oil supplement if your prescriber recommends it.
There’s some concern that fish oil supplements may actually raise the risk of heart problems in people without any underlying heart issues. Your healthcare team can help determine if an over-the-counter (OTC) or prescription fish oil supplement is a safe and appropriate option for you. They can also provide dosage guidance that’s specific to your needs.
5. What are the side effects of fish oil supplements?
Common side effects of fish oil supplements include:
Nausea
Heartburn
Loose stools
Bad taste in your mouth and/or bad breath
Fishy body odor
In most cases, you can manage these side effects by taking a fish oil supplement with food or lowering your dosage. But if they become bothersome, talk to your healthcare team for guidance.
As mentioned, high doses of fish oil may also increase your bleeding risk. So be sure to let your healthcare team know if you notice you’re bruising easier than usual or have bleeding gums when brushing your teeth. If you notice blood in your urine or stool or a bruise that continues to grow, seek emergency care. These are signs of a more serious bleeding issue.
6. How to choose a fish oil supplement
OTC dietary supplements — including fish oil — are not regulated or approved by the FDA the same way medications are. This means the safety, quality, and ingredients can vary from product to product.
Factors to consider when choosing a fish oil supplement include:
Third-party testing: Some fish oil products may contain impurities like mercury and other chemicals if not properly filtered. Look for supplements with a third-party seal, such as “USP Verified” or “NSF Certified.” These labels mean the product has been tested by an independent company for purity, potency and safety.
Clear amounts of EPA, DHA, and/or ALA: Some products list a high amount of fish oil on the front but actually only contain a small amount of omega-3s. Always check the supplement facts label to see how much omega-3 you’re actually getting.
Enteric coating: This can help prevent fishy burps and upset stomach.
The bottom line
Fish oil supplements contain omega-3 fatty acids. They can offer valuable health benefits, especially for people living with certain heart conditions. However, fish oil can raise your risk of bleeding, particularly at high doses or when combined with certain medications.
Fish oil supplements aren’t recommended for most people without a healthcare professional’s recommendation. It’s better to meet your omega-3 needs through your diet. If your prescriber recommends a fish oil supplement, be sure to choose one with third-party testing and clear labeling to help ensure your safety.
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References
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