The lakah was a bug found on the planet Arnessk. Its intestine contained a substance that acts as a powerful mind-deadening drug; according to Utu-Noranti Pralatong, just "...stick it up your nose! You'll get a jolt – wham! And for five hundred microts nothing bothers you."
It was used by John Crichton in order to protect himself from Commandant Mele-On Grayza's Heppel oil. Later, Noranti provided Crichton with "distillate of lakah", made from the substance produced by the bug, so he could forget the pain caused to him by the presence of Aeryn Sun.