Adults can take ibuprofen every 4 to 6 hours as needed, at a dose of 200 to 400 mg per dose. You should not exceed 1,200 mg in a 24-hour period when using over-the-counter strength, and you shouldn’t take it for more than 10 consecutive days for pain or 3 consecutive days for fever without checking in with a healthcare provider.
Standard Dosing for Adults
The standard over-the-counter dose for adults is 200 to 400 mg every 4 to 6 hours. For menstrual cramps specifically, the recommended dose is 400 mg every 4 hours, since starting with a higher dose early tends to work better for that type of pain. For general aches and moderate pain, 400 mg every 4 to 6 hours is typical.
Three doses of 400 mg spread across a day is the practical ceiling for most people using OTC ibuprofen, totaling 1,200 mg. Prescription doses can go higher under medical supervision, but the risks climb with the dose. The key rule: always wait at least 4 hours between doses, even if the pain returns sooner.
How Long the Effects Last
A single dose of ibuprofen typically provides pain relief for 4 to 6 hours, which is why the dosing window matches that range. Some people find the relief fades closer to the 4-hour mark, especially with more intense pain like cramps or dental pain, while others get a solid 6 hours from one dose. If you consistently find that relief wears off at the 4-hour mark, that’s fine for short-term use, but it means you’re taking more total ibuprofen per day, which matters over time.
How Many Days in a Row Is Safe
For pain, the limit is 10 days of consecutive use before you should talk to a provider. For fever, that window is shorter: just 3 days. These aren’t arbitrary cutoffs. The longer you take ibuprofen, the more it accumulates its effects on your stomach lining, kidneys, and cardiovascular system. If you still need ibuprofen after 10 days, the underlying problem likely needs its own treatment rather than ongoing pain management.
Risks of Taking It Too Often
Short courses at normal doses are generally low-risk. The real concerns emerge with high doses taken over weeks or months, the pattern common in people managing chronic conditions like arthritis.
A large study from Oxford’s Clinical Trial Service Unit found that prolonged, high-dose ibuprofen use increased the risk of a major cardiovascular event (heart attack, stroke, or cardiovascular death) by about one third. In practical terms, that translates to roughly 3 extra heart attacks per year for every 1,000 patients on long-term high-dose treatment, one of which would be fatal. The researchers emphasized that this risk applies mainly to people taking high doses over long periods, not someone using a few tablets for a sprained ankle.
Stomach and intestinal issues are more common than heart problems. Ibuprofen works by blocking an enzyme involved in inflammation, but that same enzyme helps maintain the protective lining of your stomach. Regular use increases the risk of ulcer bleeding by 2 to 4 times, depending on the dose. Taking ibuprofen at the end of a full meal or with an antacid helps buffer this effect on the stomach lining, and it’s worth doing every time you take a dose.
Your kidneys are also vulnerable. Ibuprofen reduces blood flow to the kidneys, which is usually harmless for a few days but can cause problems if you’re dehydrated, take it daily for weeks, or already have reduced kidney function.
Dosing for Children
Children 6 months and older can take ibuprofen, but the dose is based on weight, not age: 10 mg per kilogram of body weight every 6 to 8 hours. That’s a longer interval than adults, so children should wait at least 6 hours between doses. Ibuprofen is not recommended for infants under 6 months old, as it hasn’t been established as safe for that age group and isn’t FDA-approved for them.
Children’s ibuprofen comes in liquid concentrations that vary by brand, so always use the measuring device included with the product rather than a kitchen spoon. Dosing charts on the packaging typically go by weight first and age second.
Who Should Be More Cautious
Pregnant women should avoid ibuprofen at 20 weeks of pregnancy or later. The FDA issued a specific warning about this because ibuprofen use in later pregnancy can reduce amniotic fluid levels and affect fetal kidney development.
People with a history of stomach ulcers, heart disease, high blood pressure, or kidney problems face higher baseline risks from ibuprofen, even at standard doses. The same applies if you take blood thinners or other anti-inflammatory medications, since the effects on bleeding and stomach irritation compound. If you fall into any of these groups, acetaminophen is often a safer choice for routine pain, though it works differently and won’t reduce inflammation.
Making Each Dose More Effective
Taking ibuprofen with food doesn’t just protect your stomach. It also helps you absorb the medication more consistently. A full glass of water with each dose helps too, especially since dehydration makes your kidneys more vulnerable to ibuprofen’s effects.
If you’re using ibuprofen for an injury or inflammation, timing matters more than frequency. Taking it on a schedule (say, every 6 hours for 2 to 3 days) keeps a steady level of anti-inflammatory effect in your system, which works better than waiting until pain flares and chasing it with a single dose. Once the acute phase passes, switch to taking it only as needed rather than on a clock.