The antiproton injection subsystem was a component of the warp core. Resembling a hollow cylinder, this subsystem connected the antimatter chamber to the dilithium regulation chamber. This subsystem included antiproton injectors. Safety measures built into this subsystem included antiproton injection seals. If there were antiprotons in the subsystem, antiproton injection seals on the dilithium regulation chamber were designed to prevent these particles from entering into this chamber and mixing with deuterium.

Aboard Galaxy-class starships, this subsystem was located on Decks 37 to 41. (TNG: "Contagion", display graphic)