Ultrazepam

Ultrazepam was a psychotropic tranquilizer drug that was in use during the later days of the Galactic Republic. It was commonly used in common, mundane psychiatry to treat phobias, anxiety disorders and aggressive behaviour. However, the Jedi Shadows found out that the drug's effects, mainly suppression of base emotions such as fear and aggression, makes it useful for rehabilitating those who fell to the Dark Side. If ultrazepam was administered to a Dark Jedi, their ability to call on the Dark Side of the Force was greatly diminished.