Melanex was a sedative drug available in the Federation in the 23rd century.
History and specifics[]
It was considered a light sedative. (FASA RPG module: Game Operations Manual)
It produced five minutes of unconsciousness in a humanoid patient. While affected, a person's skin would turn a vivid yellow color, similar to the color of someone sedated with Melanex B. (FASA RPG module: Star Fleet Intelligence Manual)
In 2270, Phil Cooper was treated with restful semi-sedation for 18 hours aboard the starship USS Enterprise using melanex, leaving his mind foggy after he woke up. (TOS novel: Crossroad)