Gamma Butyrolactone (GBL) 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. Order GBL Liquid in Australia for the above and as a recreational drug for recreational purposes. GBL is a naturally occurring component in some wines and may be present in similar products. GBL is rapidly converted into GHB by paraoxonase (lactonase) enzymes, found in the blood.