Ibuprofen is an analgesic drug and a member of the class of drugs referred to as non-steroidal anti-inflammatory drugs (NSAIDS). It is thought to be a nonselective cyclooxygenase (COX) inhibitor, and, like other NSAIDS, may lead to discomfort and ulceration of the gastrointestinal tract.
Along with naproxen, it is the NSAID class called the propionic acid derivatives. The form used as a drug is formally the (S)-(+)-Ibuprofen isomer, although it may be sold as a racemic mixture. It is also called other names, including (2S)-2-[4-(2-Methylpropyl)phenyl]propionic acid, (S)-(+)-4-Isobutyl-alpha-methylphenylacetic acid, and (S)-(+)-2-(4-Isobutylphenyl)propionic acid.