Overview: Naproxen is a nonsteroidal anti-inflammatory drug (NSAID) used to relieve pain, reduce swelling, and lower fever. Common side effects include belly pain, upset stomach, heartburn, or. Naproxen is a nonsteroidal anti-inflammatory drug (NSAID). It works by reducing hormones that cause inflammation and pain in the body. Naproxen is used to treat pain or inflammation caused by conditions such as arthritis, ankylosing spondylitis, tendinitis, bursitis, gout, or menstrual cramps. Naproxen is a painkiller that helps relieve pain and reduce swelling (inflammation). You can buy some types from pharmacies, but others are only available with a prescription. Naproxen is a type of painkiller called a non-steroidal anti-inflammatory drug (NSAID). Naproxen is used to treat a variety of inflammatory conditions and symptoms that are due to excessive inflammation, such as pain and fever (naproxen has fever-reducing, or antipyretic, properties in addition to its anti-inflammatory activity). [10] Learn what naproxen is, how it works, common uses, side effects, and when to talk to a healthcare professional. Learn about side effects, dosage, uses, and more for naproxen, which is a generic prescription oral tablet that treats many conditions, such as arthritis. Naproxen is used as a treatment to relieve pain from various conditions such as headaches, muscle aches, tendonitis, dental pain, and menstrual cramps. It also reduces pain, swelling, and joint stiffness caused by conditions such as arthritis, bursitis, and gout attacks. Naproxen is a nonsteroidal anti-inflammatory drug (NSAID) used to relieve symptoms of arthritis (eg, osteoarthritis, rheumatoid arthritis, or juvenile arthritis) such as inflammation, swelling, stiffness, and joint pain. Learn about the side effects of naproxen, from common to rare, for consumers and healthcare professionals. View naproxen information, including dose, uses, side-effects, renal impairment, pregnancy, breast feeding, contra-indications and important safety information.