Adults can take 200 to 400 mg of ibuprofen every four to six hours as needed, with a general limit of 1,200 mg in a 24-hour period for over-the-counter use. That spacing matters: taking doses too close together increases the risk of stomach, kidney, and cardiovascular problems without providing much extra pain relief.
Standard Adult Dosing Schedule
For mild to moderate pain, the standard over-the-counter dose is 200 to 400 mg every four to six hours. Most OTC tablets are 200 mg each, so that means one to two tablets per dose. For menstrual cramps, 400 mg every four hours tends to work better than smaller doses spaced further apart. In either case, you should not exceed 1,200 mg (six OTC tablets) in 24 hours unless a doctor has specifically told you otherwise.
Prescription-strength ibuprofen can go higher, up to 3,200 mg per day for conditions like rheumatoid arthritis, but those doses are managed by a physician and come with closer monitoring for side effects.
Ibuprofen is absorbed quickly, reaching its peak level in your blood within one to two hours. Its half-life is roughly two hours, meaning the active ingredient clears your system relatively fast. That’s why you may feel the pain creep back after four to six hours and need another dose.
How Long You Can Keep Taking It
The Cleveland Clinic recommends not taking ibuprofen for more than 10 consecutive days for pain or more than 3 consecutive days for fever. If you still need it after that window, something else may be going on that warrants a closer look from a healthcare provider. Occasional use for a headache or sore muscles is very different from daily use over weeks or months, and the risks shift significantly the longer you take it.
Dosing for Children
Children’s ibuprofen doses are based on weight, not age. The medication comes as infant drops (50 mg per 1.25 mL), children’s liquid (100 mg per 5 mL), and chewable 100 mg tablets. A child weighing 24 to 35 pounds, for example, would get 5 mL of the children’s liquid or one chewable tablet per dose. A child at 48 to 59 pounds could take 10 mL of liquid or one adult 200 mg tablet.
Children follow the same four-to-six-hour spacing between doses. Ibuprofen should not be given to infants under 6 months old, and parents should check with a provider before giving it to children under 2 years old or under 12 pounds.
What Happens if You Take Too Much
Taking more than the recommended amount, whether in a single dose or by stacking doses too close together, puts stress on your stomach lining and kidneys. In the short term, you might notice nausea, stomach pain, or heartburn. Over time, frequent overuse can cause stomach ulcers or bleeding in the digestive tract.
The kidney risk is less well known but equally serious. The FDA has highlighted that in certain higher-risk people, ibuprofen and other NSAIDs can disrupt blood flow to the kidneys and trigger acute kidney injury. This can lead to hospitalization, new chronic kidney disease, or faster progression of kidney disease you already have. People who are dehydrated, who have existing kidney problems, or who take blood pressure medications are especially vulnerable. The FDA notes that patient education materials have historically focused too narrowly on bleeding risks, underplaying the potential for kidney damage.
Who Should Avoid the Standard Schedule
If you take a blood thinner, ibuprofen changes how your platelets function and can interfere with normal clotting. Combining the two raises your bleeding risk significantly, particularly in the digestive tract. Harvard Health Publishing describes this as a genuinely dangerous combination. If you’re on blood thinners and need pain relief, your options are more limited, and any NSAID use should involve the lowest possible dose for the shortest possible time.
Other groups that need to be cautious with standard ibuprofen dosing include people with a history of stomach ulcers, those with heart disease or high blood pressure, anyone with impaired kidney function, and people who drink alcohol regularly. In all of these situations, taking ibuprofen less frequently or choosing an alternative painkiller is often the safer path.
Practical Tips for Safer Use
- Start low. Try 200 mg first. If that handles the pain, there’s no reason to take 400 mg.
- Space doses fully. Wait the full six hours if you can. The four-hour minimum is for when pain is more intense, not the default.
- Take it with food. Eating something before your dose reduces irritation to the stomach lining.
- Track your doses. It’s easy to lose count, especially when you’re in pain. A note on your phone or a simple tally on paper prevents accidental double-dosing.
- Stop when you can. Ibuprofen works best as a short-term tool. Once the pain or inflammation is under control, stop taking it rather than continuing “just in case.”