Naproxen (INN; brand names: Aleve, Naprosyn and many others) is a nonselective COX inhibitor; usually sold as the sodium salt, naproxen is a nonsteroidal anti-inflammatory drug (NSAID) of the propionic acid class (which puts it in the same class as ibuprofen) commonly used for relief of a wide variety of pain, fever, swelling and stiffness.