Naproxen belongs to a group of medicines called non-steroidal anti-inflammatory drugs (NSAID). It is a painkiller and antipyretic (reduces fever). Naproxen works by reducing inflammation and relieving pain, swelling and stiffness in the joints and muscles. Naproxen is a pain-relieving medicine. It provides relief from pain and inflammation in conditions like osteoarthritis, rheumatoid arthritis, ankylosing spondylitis, gout, and juvenile arthritis. It also helps in relieving muscle and joint pain, headache, toothache, and menstrual cramps. Naproxen should be taken with food to avoid stomach upset and reduce side effects. In general, you should try to use the smallest amount necessary to control your symptoms, for the shortest possible time. You should take this medicine regularly while you need it. Try not to miss doses as it will become less effective if you do.