The deuterium injection subsystem was a component of the warp core. Resembling a hollow cylinder, this subsystem connected the deuterium tank to the dilithium regulation chamber. This subsystem included deuterium injectors. Unlike the antiproton injection subsystem, the deuterium injection subsystem lacked a spin reversal system or injection seals.

Aboard Galaxy-class starships, this subsystem was located on Decks 30 to 35. (TNG: "Contagion", display graphic)