A normal dose of ibuprofen for adults is 200 to 400 mg taken every four to six hours as needed, with a maximum of 1,200 mg in 24 hours for over-the-counter use. That’s one to two of the standard 200 mg tablets you’ll find at any pharmacy. Prescription doses can go higher, but for everyday pain relief, those numbers cover most situations.
Standard Adult Doses
The typical starting point is 200 mg, which is one standard tablet or caplet. For most headaches, minor aches, and fevers, 200 mg works fine. If that doesn’t provide enough relief, you can take 400 mg (two tablets) per dose. Space your doses four to six hours apart, and don’t exceed 1,200 mg (six tablets) in a 24-hour period when you’re self-treating.
For menstrual cramps specifically, 400 mg every four hours tends to be more effective than the lower dose, since cramps involve a stronger inflammatory response. The same 400 mg dose applies to general moderate pain like dental work, muscle strains, or back pain.
Prescription ibuprofen for chronic conditions like rheumatoid arthritis or osteoarthritis uses significantly higher amounts, ranging from 1,200 mg to 3,200 mg per day split into three or four doses. These doses require medical supervision and regular monitoring.
How It Works and How Fast
Ibuprofen blocks the enzymes your body uses to produce prostaglandins, chemicals that trigger pain, swelling, and fever at the site of an injury or illness. By reducing prostaglandin production, it lowers all three at once, which is why it’s useful for such a wide range of problems.
You can expect pain relief to kick in within 30 to 60 minutes of taking a dose, and each dose lasts roughly four to six hours. That’s the window for pain and fever. If you’re taking ibuprofen for inflammation, like a swollen joint or a sports injury, the full anti-inflammatory effect builds over one to two weeks of consistent use.
Doses for Children
Children’s ibuprofen is dosed by weight, not age. The general guideline is to give a dose every six to eight hours as needed, but the exact milligram amount depends on how much your child weighs. Children’s liquid formulations come with a dosing syringe and a weight-based chart on the packaging. Follow that chart rather than estimating, since under-dosing won’t help and over-dosing raises the risk of side effects. Ibuprofen is not recommended for infants under six months old.
Taking It With Food
Ibuprofen is easier on your stomach when you take it at the end of a full meal or with an antacid. On an empty stomach, it can irritate the stomach lining directly, which over time increases the chance of developing an ulcer. If you only need a dose here and there, an empty stomach probably won’t cause problems. But if you’re taking it for several days in a row, eating first makes a real difference in how your gut tolerates it.
Daily Limits and Duration
For self-care, the ceiling is 1,200 mg per day, and you shouldn’t use it for more than 10 consecutive days for pain (or three days for fever) without medical guidance. Going beyond those limits raises two specific risks the FDA highlights on every ibuprofen label.
The first is stomach bleeding. Your risk increases if you’re over 60, have a history of ulcers, drink three or more alcoholic beverages a day, or take blood thinners or steroid medications. Warning signs include vomiting blood, black or bloody stools, and persistent stomach pain.
The second is cardiovascular. All NSAIDs except aspirin increase the risk of heart attack, heart failure, and stroke. This risk scales with dose and duration: taking more than directed or using it for extended periods raises the likelihood. Signs to watch for include chest pain, trouble breathing, weakness on one side of the body, slurred speech, or leg swelling.
Who Should Avoid Ibuprofen
If you’re pregnant, ibuprofen carries serious risks starting at 20 weeks. The FDA warns that use at 20 weeks or later can cause kidney problems in the developing baby, potentially leading to dangerously low amniotic fluid levels. After 30 weeks, the risks increase further because ibuprofen can cause premature closure of a blood vessel in the baby’s heart that needs to stay open until birth.
People with existing kidney disease should be cautious, since ibuprofen reduces blood flow to the kidneys. The same applies to anyone with a history of stomach ulcers or gastrointestinal bleeding. If you have aspirin-sensitive asthma, ibuprofen can trigger the same reaction because it works through the same enzyme pathway.
Interactions With Other Medications
The most notable interaction is with low-dose aspirin taken for heart protection. Ibuprofen can interfere with aspirin’s ability to prevent blood clots if you take them at the same time. If you need both, timing matters: taking ibuprofen at least 30 minutes after or eight hours before your aspirin dose helps avoid the conflict.
Ibuprofen also increases bleeding risk when combined with blood thinners, and stacking it with other NSAIDs (like naproxen) compounds the risk of stomach bleeding and kidney strain without providing better pain relief. If one NSAID isn’t enough, switching to a different pain management approach is safer than doubling up.