The standard adult dose of ibuprofen is 200 to 400 milligrams every four to six hours as needed, with a maximum of six doses in 24 hours. That means most adults should not exceed 1,200 mg per day when using over-the-counter ibuprofen. The right amount for you depends on what you’re treating, your age, and your body weight if you’re dosing a child.
Standard Adult Dose
Each over-the-counter ibuprofen tablet is typically 200 mg. For general pain relief, headaches, or fever, starting with one tablet (200 mg) is often enough. If that doesn’t provide relief, you can take two tablets (400 mg) per dose. Space your doses four to six hours apart, and don’t take more than six doses (1,200 mg total) in a 24-hour period unless a doctor has told you otherwise.
For menstrual cramps, the recommended dose is 400 mg every four hours as needed. Cramp pain tends to respond better to a slightly more aggressive dosing schedule, but the same daily ceiling applies for over-the-counter use.
Prescription Doses Are Higher
Doctors sometimes prescribe ibuprofen in 600 mg or 800 mg tablets for conditions like rheumatoid arthritis, osteoarthritis, or severe inflammatory pain. At prescription strength, the daily maximum goes up to 3,200 mg, but only under medical supervision. These higher doses carry a greater risk of stomach, kidney, and cardiovascular side effects, which is why they require a prescription and monitoring.
Dosing for Children
Ibuprofen should not be given to infants under six months old. For children six months and older, the dose is based on weight rather than age. If you don’t know your child’s weight, age can serve as a rough guide, but weight is more accurate. Children’s ibuprofen comes in liquid form with a measuring syringe, and the packaging includes a dosing chart. Give it every six to eight hours as needed, not more frequently.
How Quickly It Works
Oral ibuprofen typically starts relieving pain within 30 to 60 minutes. A single dose lasts six to eight hours, which is why the recommended spacing is four to six hours. You don’t need to wait until the effects fully wear off to take your next dose, but sticking closer to six hours between doses reduces the total amount you take over the course of a day.
Taking It With or Without Food
You’ve probably heard you should take ibuprofen with food to protect your stomach. This advice is nearly universal, appearing in guidelines from health agencies in the U.S., U.K., Canada, and Germany. The logic is straightforward: ibuprofen can irritate the stomach lining, and food acts as a buffer.
Interestingly, a systematic review in the British Journal of Clinical Pharmacology found no actual evidence that taking ibuprofen with food reduces stomach side effects. Some researchers have suggested that taking it on an empty stomach is preferable when you want faster pain relief, since food slows absorption. In practice, if ibuprofen has never bothered your stomach, taking it without food for quicker relief is reasonable. If you’ve had stomach sensitivity with it before, eating something first is a sensible precaution.
Who Should Be Careful
Ibuprofen works by blocking an enzyme called COX, which reduces inflammation and pain but also affects the protective lining of your stomach and blood flow to your kidneys. This means people with a history of stomach ulcers, kidney problems, or gastrointestinal bleeding need to be particularly cautious. Long-term or high-dose use amplifies these risks.
If you take low-dose aspirin (81 mg daily) for heart protection, ibuprofen can interfere with aspirin’s ability to prevent blood clots. The FDA has specifically warned about this interaction. Ibuprofen and aspirin compete for the same binding site, and if ibuprofen gets there first, aspirin can’t do its job. If you need both, take your aspirin at least 30 minutes before ibuprofen, or take the ibuprofen at least 8 hours before your aspirin dose.
Ibuprofen also increases bleeding risk when combined with blood-thinning medications. If you’re on any anticoagulant, talk to your pharmacist before reaching for ibuprofen.
Keeping the Dose as Low as Possible
The safest approach with ibuprofen is the lowest effective dose for the shortest time. If 200 mg handles your headache, there’s no reason to take 400 mg. If your pain resolves in two days, don’t keep taking it for a week “just in case.” Over-the-counter ibuprofen is meant for short-term use, generally no more than 10 days for pain or 3 days for fever without medical guidance. Beyond that window, the risks of stomach and kidney complications start to climb.