γ-Butyrolactone (GBL) is a cyclic ester and polar aprotic solvent widely used in industrial applications including paint stripping, polymer processing, and as a precursor in the synthesis of pharmaceuticals and agrochemicals. It is a colorless, odorless liquid that is fully miscible with water and most organic solvents. In biological systems, GBL is rapidly metabolized by lactonases to γ-hydroxybutyric acid (GHB), a central nervous system depressant. It exhibits high stability under neutral conditions but hydrolyzes in the presence of strong acids or bases. GBL is employed in the food industry as a flavoring solvent in trace amounts but is strictly regulated due to its psychoactive metabolite. Its dielectric constant and solvating power make it valuable in electrochemical applications and as a reaction medium for organic synthesis.