Celecoxib is a nonsteroidal anti-inflammatory drug (NSAID) that is used to treat mild to moderate pain and to help relieve symptoms of arthritis such as inflammation, swelling, stiffness, and joint pain. It is highly selective in inhibiting COX-2, the form of cyclooxygenase expressed during inflammatory processes, while not affecting the constitutive form COX-1. This selective inhibition helps to reduce the gastric and intestinal toxicity commonly associated with non-selective NSAIDs.

In addition to treating arthritis, Celecoxib has been found effective in patients with familial adenomatous polyposis (FAP). Clinical trials have shown that Celecoxib can reduce the number of colorectal polyps in these patients. It works by reducing hormones that cause inflammation and pain in the body.