4-Methoxybenzoic acid, commonly known as p-anisic acid or anisic acid, is an aromatic carboxylic acid derived from benzoic acid with a methoxy substituent at the para position. It occurs naturally in anise, fennel, and certain mushrooms. This white crystalline solid is valued in the flavor and fragrance industry for its sweet, hawthorn-like aroma and is used as a preservative in cosmetics due to antimicrobial properties. Chemically stable under normal conditions, it serves as an intermediate in organic synthesis for pharmaceuticals and dyes. Its structure features a benzene ring with carboxylic acid and methoxy groups, conferring moderate polarity and solubility in organic solvents.