Dimitar Marinov, MD, an assistant professor in the hygiene and epidemiology department of the Medical University of Varna in Bulgaria, says that combining ibuprofen and fish oil can increase your risk of bleeding, particularly gastrointestinal bleeding. According to the Mayo Clinic, gastrointestinal bleeding can cause shock, anemia, or even death. That’s why you should discuss your medicine and vitamin regimens with your doctor just in case.ae0fcc31ae342fd3a1346ebb1f342fcb “When taking fish oil with ibuprofen, there is a moderate risk of bleeding because it is a potential side effect of both medications,” explains Chris Riley, a medication expert and CEO of USA Rx, a prescription discount company. “Therefore, when they are combined it doubles the chance of this side effect happening.” And for more on risky medication combinations, If You Take These 2 OTC Meds Together, You’re Putting Your Liver at Risk. You don’t need to worry about eating too much fish when you are taking ibuprofen, however. Chris Airey, MD, the medical director at Optimale, says that eating fish and taking ibuprofen does not come with the same risks as taking fish oil supplements with ibuprofen. “The amount of omega-3’s in a fish oil tablet is considerably more concentrated,” Airey explains, which is why they come with an added risk. And for more on fish oil, If You Take This Popular Supplement, Your Heart May Be at Risk, Study Says. Ibuprofen is a non-steroidal anti-inflammatory drug (NSAID), a type of medication that has antiplatelet properties. That means it can “thin your blood and one of the possible side effects is prolonged bleed time,” explains Jessica Nouhavandi, PharmD, lead pharmacist and founder of online pharmacy Honeybee Health. Therefore, any medication in this group, like aspirin and naproxen, could negatively interact with fish oil. Airey says that if you are taking any medication that has an effect on your blood or blood clotting, you should “seek professional medical advice before adding fish oil to your supplement regimen.” And for more up-to-date information, sign up for our daily newsletter. If you have had a negative interaction from taking ibuprofen and fish oil together, you may notice certain symptoms. According to Riley, less intense warning signs may include lightheadedness and light bruising. But if you experience any bleeding from your nose or another orifice, or if you start coughing up blood or noticing blood in your stool, you should seek medical attention immediately. Nouhavandi says you should also watch out for prolonged bleeding, or increased bruising, as well as bruises that do not go away or become swollen or painful. And for more on OTC pain relievers, This Is When You Should Take Tylenol Instead of Advil, Doctors Say.