4-methyl-GHB
γ-Hydroxyvaleric acid (GHV), also known as 4-methyl-GHB, is a designer drug related to γ-hydroxybutyric acid (GHB). It is sometimes seen on the grey market as a legal alternative to GHB, but with lower potency and higher toxicity,[2] properties which have tended to limit its recreational use.[3]
γ-Valerolactone (GVL) acts as a prodrug to GHV, analogously to how γ-butyrolactone (GBL) is a prodrug to GHB.[4]