Does fish oil cause bruising?
By Margaret Hale, Reunoa EditorialLast updated
The short answer
Fish oil slightly reduces how sticky platelets are, so some people notice more bruising. But large reviews of randomized trials found omega-3 supplements were not linked to a meaningful increase in bleeding overall; very high-dose purified EPA may add a small risk. If you bruise easily or take a blood thinner, tell your doctor or pharmacist that you take fish oil.
Fish oil is one of the most popular supplements after 60, often taken "for the heart" or joints. It also has a reputation for "thinning the blood". If you bruise easily, it's worth knowing what the evidence actually says.
What fish oil does to platelets
The omega-3 fats in fish oil (EPA and DHA) make platelets a little less likely to clump. A systematic review confirmed that fish oil reduced platelet aggregation in healthy people [2]. In theory, that could mean more bruising.
Does that translate into more bleeding?
Mostly not, according to the trials:
- A 2024 meta-analysis of 11 randomized trials with more than 120,000 people found omega-3 supplements were not associated with an increased risk of bleeding overall. People taking high-dose purified EPA may have a small additional risk, described as "very modest" [1].
- A 2017 systematic review found fish oil did not increase bleeding during or after surgery, despite its effect on platelets [2].
So, fish oil at usual doses is unlikely to be the main reason for frequent bruises. It can still add a little on top of other causes — especially in someone already on blood thinners.
Fish oil with blood thinners
The NIH's integrative health center describes side effects of omega-3 supplements as usually mild and advises telling your health care providers about any supplements you use [3]. Warfarin drug information also asks you to tell your doctor about all supplements you take [4] — fish oil is one of the supplements pharmacists commonly ask about.
What to do:
- Tell your doctor and pharmacist you take fish oil — include the dose.
- Don't add high-dose fish oil while on Eliquis, Xarelto, warfarin, Plavix or aspirin without asking.
- Don't stop a prescribed omega-3 product (such as icosapent ethyl) without talking to your doctor.
Other supplements that may add to bruising
Vitamin E, ginkgo, garlic pills, turmeric/curcumin and high-dose ginger are commonly mentioned for possible effects on bleeding. If you take several, bring the bottles to your next appointment.
If you bruise easily
Fish oil is rarely the whole story. Thin, sun-aged skin, blood thinners, steroids and low vitamin C or K are more common causes. See why do I bruise so easily? and bruising on blood thinners.
Frequently asked questions
Can fish oil make you bruise more easily?
It can slightly, because omega-3s make platelets less sticky. But large trial reviews found no meaningful overall increase in bleeding at usual doses.
Should I stop fish oil before surgery?
A systematic review found no increased surgical bleeding with fish oil. Still, follow your surgeon's instructions; many give a standard list of supplements to pause.
Is it safe to take fish oil with Eliquis or warfarin?
Ask your doctor or pharmacist. At usual doses trials show little extra bleeding, but high doses — especially purified EPA — may add a small risk on top of a blood thinner.
How much fish oil is too much?
Supplement doses vary widely. Doses above what is on most labels should be discussed with a doctor, especially if you take blood thinners or bruise easily.
Sources
- Javaid M, et al. Bleeding Risk in Patients Receiving Omega-3 Polyunsaturated Fatty Acids: A Systematic Review and Meta-Analysis of Randomized Clinical Trials. Journal of the American Heart Association, 2024. PubMed 38742535
- Begtrup KM, et al. No impact of fish oil supplements on bleeding risk: a systematic review. Danish Medical Journal, 2017. PubMed 28552094
- Omega-3 Supplements: What You Need To Know — NCCIH (NIH).
- Warfarin — Drug Information — MedlinePlus.
- Blood Thinners — MedlinePlus (U.S. National Library of Medicine).
- Bleeding into the skin — MedlinePlus Medical Encyclopedia (U.S. National Library of Medicine).
General information, not medical advice. Written by the Reunoa editorial team; Reunoa makes Bruise Defense & Repair Serum. See our editorial policy for how we pick sources and keep product mentions fair.