Ibuprofen is a derivative of propionic acid that was originally marketed in the United States as an antirheumatic agent in 1974. In 1979, it was approved for use as an analgesic. Of the 18 published double-blind clinical trials reviewed, only 6 were well designed. These six studies provide strong evidence that ibuprofen is effective for dental pain due to tooth extractions, dysmenorrhea and episiotomy pain. Thus, ibuprofen appears to be an effective drug for mild to moderate pain. It is as effective or more effective than aspirin, codeine or propoxyphene. Recommended initial dosage is 300 mg every six hours, increasing as needed to 400 mg every four hours. Adverse effects are relatively minor and infrequent.