The normal dosage for ibuprofen varies based on age and the medical condition it treats, explains Mayo Clinic. Adults and teenagers experiencing mild to moderate pain typically take 400 milligrams every four to six hours, as needed. A doctor should determine the appropriate dose for infants or children.
Adults and teenagers with rheumatoid arthritis or osteoarthritis typically take between 1,200 to 3,200 milligrams of ibuprofen per day, separated into three or four equal-sized doses, according to Mayo Clinic. Women suffering from menstrual cramps typically take 400 milligrams of ibuprofen every four hours, as needed. Taking too much ibuprofen increases the likelihood of unwanted side effects.