It's promptly converted into GHB by lactonase enzymes located in the blood.[5] GBL is a lot more lipophilic (Unwanted fat soluble) than GHB, and so is absorbed quicker and it has greater bioavailability; paradoxically This could certainly indicate that GBL has a speedier onset of effects than GHB by itself, https://bestchemshop.com/product/gamma-butyrolactone-gbl-liquid/