This article analyzes nonsteroidal anti-inflammatory drugs (NSAIDs) and their mechanisms of action, side effects, and safety. Most NSAIDs inhibit both cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2), which can lead to unwanted side effects from decreased prostaglandin formation, particularly those causing gastric ulcers. Selective COX-2 inhibitors were developed to reduce these side effects while maintaining analgesic effects. The article discusses the roles of COX-1 and COX-2 in prostaglandin synthesis and various physiological processes. It also summarizes the potential side effects of NSAIDs on the gastric mucosa, kidneys,