A stimulant, also referred to as a stim, was a chemical mixture targeted towards the adrenal system, in the form of a one-time use shot, that was injected into the bloodstream in order to provide a boost to the physical capabilities of the user. This enhancement was most commonly used by individuals that were preparing for or already in the midst of a battle. The MandalorianCanderous Ordo was known to have been adept at preparing stims, which he freely offered to both Revan[1] and the Jedi Exile[2] during his travels with them.
The effect was described as "like ten hours of good, deep sleep, and four square meals" until they wore off. [3]