The invention relates to a drug delivery device (1) for dispensing a dose of a drug, comprising:- a support body (2) having a first end defining a first opening and a second end defining a second opening,- a syringe barrel (5) sealed by a stopper (7) slidably disposed therein along an axial direction and adapted to have an integrated needle (6) or to be coupled with a needle assembly comprising a needle (6), wherein the syringe barrel (5) is positioned within the support body (2),- a protective needle boot (11) arrangeable over the needle (6) on the syringe barrel (5),- a needle shield (4) adapted to be coupled to one of the ends of the support body (2) and slidable with respect to the support body for covering or exposing the needle (6)- a locking collar (12) positioned in the support body (2), the locking collar (12) comprising a blocking protrusion (12.1) for obstructing movement of the needle shield (4) relative to the support body (2).
