Salicylic acid is a white crystalline organic compound with the formula C7H6O3. It is a phenolic derivative of benzoic acid. Salicylic acid occurs naturally in plants, where it serves as a precursor to the biosynthesis of other important plant metabolites. Salicylic acid is also an important plant hormone. It is used in the production of aspirin, which is a common drug used to treat pain and fever.