γ-Butyrolactone (GBL) is a hygroscopic colorless, water-miscible liquid with a weak characteristic odor. It is the simplest 4-carbon lactone. It is mainly used as an intermediate in the production of other chemicals, e.g. methyl-2-pyrrolidone. In humans GBL acts as a prodrug for γ-hydroxybutyric acid (GHB), and it is used as a recreational CNS depressant with effects similar to barbiturates.

GBL is a chemical. People use it as medicine. Be careful not to confuse gamma butyrolactone (GBL) with gamma hydroxybutyrate (GHB).

Industrial use

Gamma-Butyrolactone (GBL) has widespread industrial use. It is a common solvent found in paint strippers, nail polish removers, stain removers and circuit board cleaners. It is also a common intermediate in industrial chemistry including the manufacture of pyrrolidones and in some pharmaceuticals.

Despite serious safety concerns and illegality, people take gamma butyrolactone for improving athletic performance, sleep, and sexual performance and pleasure. They also take it for relieving depression and stress, prolonging life, promoting clear thinking, causing relaxation, and releasing growth hormone. GBL is also used to trim fat and as a body- or muscle-builder. Some people take it as a recreational drug.

One significant use of GBL is as an intermediate in the manufacture of pyrrolidones, which are widely used industrial chemicals. A second significant use of GBL, because of its strong solvency properties, is in cleaning products such as circuit board cleaners in electronics, in paint strippers and as a component of nail polish removers. It is used as a solvent for polyacrylonitrile, cellulose acetate, methylacrylate polymers, and polystyrene. Other applications include the production of herbicides and pharmaceuticals, and is used as an intermediate in the synthesis of DL-methionine, piperidine, phenylbutyric acid and thiobutyric acid.