For most adults, the standard single dose of ibuprofen is 200 to 400 mg taken by mouth. That’s one to two over-the-counter tablets (each tablet is typically 200 mg). A 400 mg single dose is the most commonly recommended amount for pain, fever, and menstrual cramps, and it’s also the ceiling for self-treating without a prescription.
OTC vs. Prescription Doses
Over-the-counter ibuprofen tops out at 400 mg per dose and 1,200 mg per day (three doses of 400 mg). Most OTC labels suggest starting with 200 mg and only going up to 400 mg if the lower dose isn’t enough. You can repeat a dose every four to six hours, but should not take more than six individual doses (of 200 mg each) in 24 hours.
Prescription ibuprofen goes higher. For chronic conditions like osteoarthritis or rheumatoid arthritis, doctors may prescribe up to 3,200 mg per day, split into three or four doses. That works out to 800 mg per dose taken three or four times daily. An 800 mg single dose is the highest amount typically prescribed, and it’s only appropriate under medical supervision for ongoing inflammatory conditions, not for the occasional headache.
How Spacing Matters
The minimum gap between doses is four hours for adults, though six to eight hours is gentler on your stomach. For menstrual cramps specifically, 400 mg every four hours as needed is a standard recommendation. For general pain or fever, every four to six hours is typical.
The reason timing matters: ibuprofen works by blocking the production of prostaglandins, chemicals your body makes that trigger pain, swelling, and fever. It also blocks prostaglandins that protect the lining of your stomach. Taking doses too close together increases exposure and raises the risk of stomach irritation, heartburn, or in more serious cases, bleeding in the digestive tract.
Doses for Children
Children’s doses are based on weight, not age, whenever possible. Ibuprofen should not be given to infants under 6 months old. For children 6 months and older, the dose is calculated by body weight and given every six to eight hours, with a maximum of four doses in 24 hours. Children’s formulations come as liquid suspensions and chewable tablets with lower concentrations than adult pills, so always check the label or packaging chart that matches your child’s weight range.
Who Should Avoid Ibuprofen
Ibuprofen interferes with how blood platelets clump together, which means it affects clotting. If you take a blood thinner, combining it with ibuprofen raises the risk of bleeding significantly, particularly in the digestive tract. This applies to both prescription blood thinners and daily aspirin therapy.
People with kidney disease need to be cautious as well. Ibuprofen reduces blood flow to the kidneys, which can worsen existing kidney problems or cause damage with prolonged use. The same applies to people with a history of stomach ulcers, heart failure, or liver disease. If any of these apply to you, a different pain reliever is likely a better choice.
Signs You’ve Taken Too Much
An ibuprofen overdose can range from uncomfortable to dangerous depending on the amount. Mild overdose symptoms include nausea, vomiting, stomach pain, and headache. More concerning signs include ringing in the ears, blurred vision, confusion, and difficulty breathing. Severe overdoses can cause seizures, extremely low blood pressure, little to no urine output, and loss of consciousness.
If you accidentally double up on a dose (taking 800 mg instead of 400 mg as a one-time mistake), serious harm is unlikely for a healthy adult, but you should skip or delay your next dose to stay within the daily limit. If someone has taken a large amount intentionally or a child has swallowed multiple tablets, call Poison Control (1-800-222-1222 in the U.S.) or seek emergency care immediately.
Practical Tips for Safe Use
- Start low. Try 200 mg first. Many people get adequate relief without needing 400 mg.
- Take it with food or water. This reduces the chance of stomach irritation.
- Keep it short-term. OTC ibuprofen is meant for temporary use, generally no more than 10 days for pain or 3 days for fever unless directed otherwise.
- Watch for stacking. Many cold, flu, and migraine combination products contain ibuprofen. Check ingredient lists to avoid accidentally doubling your dose.
- Don’t mix NSAIDs. Taking ibuprofen alongside naproxen or aspirin increases side effects without improving pain relief.