The over-the-counter painkiller carries FDA-approved label warnings that most people never read. The federal guide to food-drug interactions issued by the FDA and the National Consumers League warns that non-steroidal anti-inflammatory drugs, the class that includes ibuprofen, can cause stomach bleeding.
The single clearest label warning concerns alcohol. According to the FDA guide, people who have three or more alcoholic drinks every day should check with a doctor before taking NSAIDs, because the chance of stomach bleeding is higher.
Taking ibuprofen on an empty stomach adds another layer of risk. The FDA guide recommends taking NSAIDs with food or milk if they upset the stomach.
MedlinePlus, the consumer health service of the U.S. National Library of Medicine, notes that NSAIDs such as ibuprofen may cause ulcers, bleeding, or holes in the esophagus, stomach or intestine.
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The blood thinner combination
Mixing ibuprofen with anticoagulants, often called blood thinners, is one of the most dangerous everyday combinations. A Danish study of 51,794 patients on anticoagulants, published in the European Heart Journal in November 2024, found that adding an NSAID roughly doubled the risk of a bleed.
For ibuprofen specifically, the risk was 1.79 times higher than without an NSAID. The increase was not limited to the gut. Bleeding in the brain rose to more than triple the baseline risk.
"We found that for patients taking blood thinners for blood clots in the legs or lungs, using NSAIDs doubled the risk of bleeding compared with not using NSAIDs," said Søren Riis Petersen of Aarhus University Hospital, one of the study's authors.
MedlinePlus also advises telling the doctor about any anticoagulants, aspirin or other NSAIDs before starting ibuprofen. Combining two NSAIDs at the same time drives up the same bleeding risk.
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Kidneys, sodium and long-term use
The stomach isn't the only organ at risk. NSAIDs can also affect the kidneys, especially with prolonged use.
"NSAIDs can negatively affect kidney function," notes Theodore R. Fields, MD, an attending physician at Hospital for Special Surgery in New York and professor of clinical medicine at Weill Cornell Medical College.
Fields advises watching for warning signs. Cloudy or bloody urine, a sudden drop in the amount of urine passed, or new ankle swelling can all point to kidney trouble.
That last symptom can also indicate fluid retention, one reason NSAIDs can push blood pressure up. HSS urges anyone on medication for high blood pressure to have it monitored regularly during NSAID use, and to limit alcohol because alcohol also irritates the stomach.
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The practical takeaway is straightforward. Take ibuprofen with food and a full glass of water, keep alcohol modest, avoid stacking it with other NSAIDs, and tell your doctor about any blood thinners or blood pressure medications you take. If you reach for ibuprofen most days, that on its own is a reason to check in with a clinician.
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This article is made and published by Jesper Bengtson, who may have used AI in the preparation.