Smelling salts

Members of the Preachers, such as Jake Simmonds, used what appeared to be but were "stronger" than smelling salts, which could render humans unconscious. (TV: The Age of Steel)

Saborian smelling salts were a type of potent smelling salts that were banned in seven galaxies. The Eleventh Doctor used them to revive Rory Williams after he had been taken to a Shakri ship. (TV: The Power of Three)