Ibuprofen: what it treats, how to take it, side effects
Last updated September 3, 2026.
Ibuprofen is a nonsteroidal anti-inflammatory drug (NSAID) used for pain, fever, and inflammation. It works by stopping the body's production of a substance that causes pain, fever, and swelling. It is sold over the counter (Advil, Motrin, and generics) and in higher-strength prescription tablets.
What does it treat?
Over-the-counter ibuprofen reduces fever and relieves minor aches from headaches, muscle aches, arthritis, menstrual periods, the common cold, toothaches, and backaches. Prescription ibuprofen (400 mg, 600 mg, and 800 mg tablets on the label) treats the pain, tenderness, swelling, and stiffness of osteoarthritis and rheumatoid arthritis, plus mild to moderate pain including menstrual pain.
How do you take it?
For over-the-counter use, adults and children over 12 can usually take a dose every 4 to 6 hours as needed for pain or fever, with no more than 6 doses in 24 hours. Take it with food or milk to prevent stomach upset. Prescription dosing for arthritis is typically three or four times a day as your doctor directs. Two limits from MedlinePlus matter: stop and call your doctor if pain lasts more than 10 days or fever lasts more than 3 days on the OTC product, and check other medicines before combining - many cough, cold, and flu products also contain ibuprofen, and doubling up can cause an overdose. If you take it on a schedule and miss a dose, take it when you remember unless the next one is close; never double up.
Side effects to know
- Common: constipation, gas or bloating, dizziness, nervousness, and ringing in the ears.
- Serious: the boxed warning class risks - NSAIDs like ibuprofen can raise the risk of heart attack and stroke, and can cause ulcers, bleeding, or holes in the stomach or intestine, sometimes without warning. Warning signs include stomach pain, heartburn that will not quit, vomit that is bloody or looks like coffee grounds, and black or tarry stools. Also report unexplained weight gain, swelling, shortness of breath, yellowing skin or eyes, rash or blisters, or cloudy or bloody urine.
Who should not take it?
Do not take ibuprofen right before or after coronary artery bypass graft (CABG) surgery, and do not take it after a recent heart attack unless your doctor tells you to. Avoid it if you have had an allergic reaction to ibuprofen, aspirin, or another NSAID. MedlinePlus says not to take it around or after 20 weeks of pregnancy unless your doctor directs it, because it may harm the fetus and complicate delivery. The risk of stomach bleeding is higher if you are older, in poor health, a smoker, or drink large amounts of alcohol. Tell your doctor if you take blood thinners, aspirin, other NSAIDs, oral steroids, or SSRI/SNRI antidepressants - the combination raises bleeding risk.
When is it an emergency?
Call 911 for chest pain, shortness of breath, weakness in one part or side of the body, or slurred speech - possible heart attack or stroke. Get immediate care for vomit that looks bloody or like coffee grounds, or black and tarry stools, which signal internal bleeding. Call 911 for an allergic reaction with swelling of the face or throat or trouble breathing. For an overdose, call Poison Control at 1-800-222-1222. Pymander's escalation routing is built and tested specifically for this class of decision; see the safety architecture working paper.
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Common questions
How much ibuprofen can I take in one day?
For over-the-counter ibuprofen, MedlinePlus gives the rule for adults and children over 12: one dose every 4 to 6 hours as needed, and no more than 6 doses in 24 hours. Prescription doses (400 mg, 600 mg, or 800 mg tablets) are set by your doctor - never exceed the amount on your prescription label.
Should I take ibuprofen with food?
It is a good idea. MedlinePlus says ibuprofen may be taken with food or milk to prevent stomach upset, which matters because the drug's main risks involve the stomach and intestine.
Can I drink alcohol while taking ibuprofen?
Heavy drinking is a real problem here. MedlinePlus lists drinking large amounts of alcohol while taking ibuprofen as one of the factors that raises the risk of ulcers and stomach or intestinal bleeding. Talk to your doctor about how much, if any, alcohol is safe for you while using it.
Can I take ibuprofen with my daily low-dose aspirin?
Timing matters. The FDA label shows ibuprofen can interfere with aspirin's antiplatelet (heart-protective) activity; the interference was minimized when immediate-release aspirin was taken at least 2 hours before a once-daily ibuprofen dose. Do not adjust this on your own - ask your doctor or pharmacist to set the timing.
How long does ibuprofen take to work?
The FDA label notes that peak levels of ibuprofen in the blood are generally reached one to two hours after a dose. Most people notice pain or fever relief starting within that window.
Is ibuprofen safe during pregnancy?
Not in the second half. MedlinePlus warns that ibuprofen may harm the fetus and cause problems with delivery if taken around 20 weeks of pregnancy or later, and says not to take it then unless your doctor specifically directs it. Earlier in pregnancy, ask your doctor before using it.
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