This article describes the status of Xyrem as a prescription drug. To learn about the chemical and its biological mode of action, see the article on gamma-hydroxybutyric acid. Xyrem is a trade name for gamma-hydroxybutyric acid or GHB, an endogenous neurochemical involved in regulating metabolism, especially regarding sleep or hibernation. In medical contexts GHB is often called sodium oxybate, which is an alternate term for the sodium salt of the chemical. Approval Process and Legal Status GHB… (More on Xyrem)