The standard adult dose of ibuprofen is 200 mg to 400 mg per dose, taken every four to six hours as needed. Most over-the-counter tablets come in 200 mg strength, and the typical starting point for a headache, muscle ache, or fever is one or two of those tablets. The maximum you should take without a prescription is 1,200 mg in a 24-hour period.
Standard Adult Doses
For mild to moderate pain, the recommended dose is 400 mg every four to six hours. For menstrual cramps, the same 400 mg dose applies but can be taken every four hours if needed. These are the doses listed by the Mayo Clinic for over-the-counter use, and they cap out at 1,200 mg per day (three doses of 400 mg).
Prescription-strength ibuprofen goes higher. For conditions like rheumatoid arthritis or osteoarthritis, doctors may prescribe anywhere from 1,200 mg to 3,200 mg per day, divided into three or four doses throughout the day. The familiar 800 mg prescription tablet is the most common form at this level. The general principle with ibuprofen at any dose is to use the lowest amount that controls your symptoms, for the shortest time possible.
Dosing for Children
Children’s ibuprofen is dosed by weight, not age. If you know your child’s weight, use that to determine the right amount. The packaging on children’s liquid ibuprofen includes a dosing chart matched to weight ranges. Ibuprofen should not be given to babies under 6 months old, as it has not been established as safe for that age group and is not FDA-approved for infants that young.
For children old enough to take it, doses are given every 6 to 8 hours, which is a slightly longer gap than the adult interval. Children’s formulations come in liquid suspensions and chewable tablets with lower concentrations, so always check the product label rather than cutting adult tablets.
How Long to Wait Between Doses
The minimum gap between adult doses is four hours, though six hours is more common for general pain relief. Taking doses closer together than four hours increases the risk of stomach irritation and kidney strain without improving pain control. Ibuprofen reaches peak levels in your blood within one to two hours, so if a dose hasn’t helped after two hours, taking more sooner won’t meaningfully change the outcome.
When Higher Doses Become Risky
The risk of side effects climbs with both dose and duration. Stomach ulcers, intestinal bleeding, and kidney problems are the main concerns. Your risk of gastrointestinal bleeding goes up further if you smoke, drink alcohol, are over 65, take corticosteroids or blood thinners, or have a history of stomach ulcers.
People with reduced kidney function face stricter limits. For those with moderately impaired kidneys, the recommended ceiling drops to 1,200 mg per day. For those with more significant kidney disease, ibuprofen is contraindicated entirely because the kidneys can’t clear the drug efficiently, leading to accumulation and further kidney damage.
Warning signs that ibuprofen is causing a problem include nausea, stomach pain, black or tarry stools, unusual fatigue, swelling in the hands or feet, or yellowing of the skin or eyes. Any of these warrant stopping the medication.
Toxicity Levels
In accidental overdose situations, toxicity thresholds are measured by body weight. Ingesting less than 100 mg per kilogram of body weight is unlikely to cause serious harm. For a 70 kg (154 lb) adult, that works out to about 7,000 mg, well above any recommended dose but far below life-threatening territory. Severe toxicity, including gastrointestinal bleeding, kidney failure, and fluid in the lungs, is associated with ingestions above 400 mg per kilogram. These numbers matter most in pediatric poisoning scenarios, where a child may swallow multiple tablets at once.
Ibuprofen and Aspirin Timing
If you take daily low-dose aspirin for heart protection, the timing of your ibuprofen matters. Ibuprofen can block aspirin’s blood-thinning effect if taken too close together. The FDA recommends taking ibuprofen at least 30 minutes after your aspirin, or at least 8 hours before it. This spacing allows aspirin to do its job on platelets before ibuprofen competes for the same binding site. If you take enteric-coated aspirin, the timing may differ, so check with a pharmacist.
Quick Reference by Use
- General pain or fever: 200 to 400 mg every 4 to 6 hours, up to 1,200 mg per day (OTC)
- Menstrual cramps: 400 mg every 4 hours as needed
- Arthritis (prescription): 1,200 to 3,200 mg per day, divided into 3 or 4 doses
- Children over 6 months: weight-based dosing every 6 to 8 hours