Narco-mist was a medicinal agent sprayed on the body of an injured being in order to help speed their recovery; it took the form of a reddish chemical mist. The patient did not feel any pain when the substance was applied. This spray was once applied to Han Solo by a Wheel medi-droid after his gladiator fight in The Big Game, which had been staged by Simon Greyshade during his stay on the space station known as The Wheel.
The effects of narco-mist were not unlike those of bacta, which could also be applied in the form of a misty spray.
- The Complete Star Wars Encyclopedia