The standard single dose of ibuprofen for adults is 200 to 400 mg, taken every four to six hours as needed. That means one to two of the common 200 mg tablets you’d pick up at a drugstore. The 400 mg upper limit per dose applies whether you’re treating a headache, muscle pain, or menstrual cramps.
Single Dose Limits for Adults
Over-the-counter ibuprofen tablets typically come in 200 mg strength. The label directions say to take one tablet every four to six hours, or two tablets if one isn’t enough. Two tablets (400 mg) is the maximum recommended single dose for self-treating adults and teenagers.
Under a doctor’s supervision, prescription ibuprofen can be dosed higher for inflammatory conditions like rheumatoid arthritis, sometimes reaching 600 or 800 mg per dose. But those higher amounts are prescribed with specific monitoring in mind and aren’t meant for casual, at-home use. If you’re buying ibuprofen off the shelf and managing everyday pain, 400 mg at a time is your ceiling.
How Long to Wait Between Doses
You need at least four to six hours between doses. For most pain, spacing doses every six hours is a reasonable approach that keeps the total daily amount lower. Menstrual cramps tend to respond better to a four-hour schedule at 400 mg per dose, since the pain often returns faster.
The total you take in 24 hours matters just as much as the single dose. For OTC use, that daily cap is 1,200 mg (three doses of 400 mg). Prescription use under medical supervision can go up to 3,200 mg per day, but again, that involves a doctor tracking your response and side effects.
Dosing for Children
Children’s doses are calculated by weight, not age. The standard range is 4 to 10 mg per kilogram of body weight per dose, given every six to eight hours. A 20 kg (44 lb) child, for example, would take somewhere between 80 and 200 mg per dose. The maximum single dose for any child is 400 mg, and the daily total should not exceed 40 mg per kilogram or 1,200 mg, whichever is lower.
Children’s liquid ibuprofen comes with a dosing syringe or cup marked with weight-based amounts. Using that tool rather than estimating with a kitchen spoon prevents both underdosing and overdosing.
What Happens if You Take Too Much
Ibuprofen has a relatively wide safety margin compared to some other pain relievers. Doses under 100 mg per kilogram of body weight generally cause minimal symptoms. For a 70 kg (154 lb) adult, that’s roughly 7,000 mg, well above what anyone should take on purpose but far above an accidental extra tablet.
Serious, life-threatening toxicity typically doesn’t appear until ingestion reaches 400 mg per kilogram or more. At that level, symptoms can include seizures, dangerously low blood pressure, slowed breathing, and kidney and liver damage. In children, severe toxicity from large accidental ingestions is more of a concern because their body weight is lower, so the mg-per-kilogram threshold is crossed more easily.
None of this means that modest overuse is harmless. Taking 600 or 800 mg on your own, or exceeding 1,200 mg in a day without medical guidance, won’t likely cause acute toxicity, but it does raise the risk of the side effects described below.
Who Should Take Less or Avoid It
Ibuprofen reduces pain partly by blocking substances that also protect your stomach lining and help regulate blood flow to your kidneys. That’s why certain conditions make even normal doses risky.
People with kidney disease need longer intervals between doses because their bodies clear the drug more slowly. In some situations, ibuprofen should be avoided entirely: if you have heart failure, liver cirrhosis, or conditions that reduce blood volume, your kidneys depend heavily on the very mechanisms ibuprofen suppresses. Taking it can tip kidney function from stable to impaired.
Stomach and intestinal bleeding is the other major concern. If you’ve had ulcers, take blood thinners, or drink alcohol regularly, ibuprofen increases your bleeding risk at any dose. The risk climbs with higher doses and longer use.
People over 65 are more vulnerable to both the kidney and stomach effects. Starting at the lowest effective dose, 200 mg, and using it for the shortest time possible reduces the chance of complications at any age, but especially in older adults.
Getting the Most From a Single Dose
Taking ibuprofen with food or a full glass of water helps protect your stomach without meaningfully slowing pain relief. On an empty stomach, standard tablets typically reach peak levels in the blood within one to two hours. Food may delay that by a small amount, but the tradeoff in stomach comfort is worth it, especially if you’re taking doses repeatedly over several days.
If 400 mg isn’t controlling your pain, taking more won’t necessarily work better. Beyond a certain point, higher doses add side-effect risk without much additional relief. Alternating ibuprofen with acetaminophen (a different type of pain reliever that works through a separate mechanism) is a common strategy that can improve pain control without increasing the dose of either drug.