Acetylsalicylic acid (C₉H₈O₄), commonly known as aspirin, is an organic compound and a derivative of salicylic acid. As a chemical reagent, it is used in laboratories for organic synthesis, analytical chemistry, and as a standard in pharmaceutical assays. It is widely used as a pain reliever for mild to moderate pain, including headaches, toothaches, and muscle aches. It also serves as an anti-inflammatory agent, helping to reduce swelling and inflammation in conditions like arthritis. Additionally, it is commonly used as an antipyretic to lower fever. In low doses, it is often prescribed to prevent heart attacks and strokes by inhibiting blood clot formation. Its ability to reduce the risk of certain cancers, particularly colorectal cancer, is also being studied. However, its use requires caution due to potential side effects like gastrointestinal irritation or bleeding.