A white liquid drug -- characterized by Deep Space Nine's chief medical officer, Doctor Bashir, as an "isogenic enzyme" -- to which the Jem'Hadar were genetically bred to addiction by the Founders.

As distributed by Vorta field supervisors, the standard Jem'Hadar uniform includes a tube that carries the ketracel-white from a replaceable holding vial in the collarbone area directly into the neck. Without "white," Jem'Hadar exhibit almost immediate and severely painful withdrawal symptoms, some of which include weakness, extreme tactile sensitivity, and apparent abdominal pain. The end result is finally death.

Until stardate 49066 -- when Doctor Bashir and Chief O'Brien were taken prisoner by an isolated group of Jem'Hadar soldiers in the Delta Quadrant -- no Jem'Hadar had been known to survive without white. The anomaly is discovered to be a genetic mutation unique to that individual.