The standard single dose of ibuprofen for adults is 200 to 400 mg, which means one to two over-the-counter tablets (each tablet is typically 200 mg). You can take this dose every four to six hours as needed, but you should not exceed 1,200 mg in a 24-hour period when using OTC ibuprofen without medical guidance.
Standard Adult Dosing
Most OTC ibuprofen tablets contain 200 mg each. For general pain relief, you can take one or two tablets (200 to 400 mg) at a time. The spacing matters just as much as the dose: wait at least four to six hours before taking another dose. At 400 mg per dose, that gives you a maximum of three doses spread across a day.
For menstrual cramps specifically, the effective dose is 400 mg (two tablets) every four hours as needed, which can push the daily total slightly higher. Under a doctor’s supervision, prescription-strength ibuprofen for conditions like rheumatoid arthritis or osteoarthritis can go as high as 3,200 mg per day, divided into three or four doses. That’s a clinical dose, not something to self-prescribe.
How Quickly It Works
Ibuprofen typically starts relieving pain within 30 to 60 minutes of taking it. The effects last roughly four to six hours, which is why the dosing schedule follows that same window. If you take a dose and don’t feel relief within an hour, taking more won’t help and only increases side-effect risk. Give it time to reach full effect before deciding the dose wasn’t enough.
Why Taking Too Much Is Risky
Ibuprofen works by blocking enzymes in your body that produce chemicals responsible for pain, inflammation, and fever. The problem is that it also blocks the version of those enzymes that protects the lining of your stomach and intestines from digestive acids. At recommended doses, this tradeoff is manageable. At higher doses or over longer periods, the protective lining breaks down, leading to stomach ulcers, bleeding, or kidney problems.
Ingestions under 100 mg per kilogram of body weight are unlikely to cause toxicity. For a 70 kg (154 lb) adult, that’s about 7,000 mg, well above the recommended daily maximum. But doses above 400 mg per kg carry significant toxicity risk, and chronic overuse at much lower levels can still cause serious organ damage over time. Symptoms of an overdose are often gastrointestinal at first: nausea, vomiting, and stomach pain.
Who Should Take Less or Avoid It
The 1,200 mg daily limit assumes you’re a generally healthy adult. Several conditions change the equation. People with reduced kidney function, heart disease, or high blood pressure should avoid ibuprofen unless specifically cleared by a doctor. If you already have kidney disease, regular ibuprofen use can accelerate the decline. Alcohol also increases the risk of stomach bleeding when combined with ibuprofen, so avoid mixing the two.
If you take other prescription medications, particularly blood thinners, blood pressure drugs, or other anti-inflammatory medications, there’s a real risk of interactions. Combining ibuprofen with another NSAID like naproxen doubles the strain on your stomach lining and kidneys without meaningfully improving pain relief.
Dosing for Children
Children’s ibuprofen dosing is based on weight, not age, and comes in lower-concentration liquid forms with a measuring syringe. Ibuprofen should not be given to infants under six months old. For older children, the packaging includes weight-based dosing charts. Using the adult tablet form for children is risky because the margin for error is much smaller in a lighter body.
Making Each Dose Count
If you find yourself regularly maxing out at 1,200 mg per day and still not getting adequate relief, the answer isn’t to take more. At that point, the pain likely needs a different approach. Taking ibuprofen with food can reduce stomach irritation and may help with absorption. Staying at the lowest effective dose for the shortest time possible is the safest strategy, even when the pain is persistent.