Dose adjustment mechanism for a medicament delivery device, preferably a resettable medicament delivery device, the mechanism comprising: a dose adjustment member (3), a driving member (4), for actuating a piston rod during dose dispensing, the actuator member (4) comprising a proximal actuator member (4 ") and a distal actuator member (4 '), a first clutch for releasably engaging the proximal actuator member (4" ) and the distal drive member (4 '), spring means (7) for loading the proximal drive member (4 ") and the distal drive member (4') in the coupled state during dose adjustment and dose dispensing, and application means (3a, 4a) associated with the proximal actuating member (4 ") and the dose adjustment member (3), characterized in that the application means (3a, 4a) comprise hooks (4a ) provided on fingers qu and protrude from the proximal end of the proximal actuating member (4 ") and a flange (3a) protruding inwardly over the proximal end of the dose adjusting member (3), such that the proximal actuating member ( 4 ") draws the dose adjustment member (3) in the distal direction during dose dispensing but allows relative axial movement of the proximal actuating member (4") relative to the dose adjustment member (3) in the proximal direction.Mecanismo de ajuste de dosis para un dispositivo de entrega de medicamento, preferiblemente un dispositivo de entrega de medicamento reiniciable, comprendiendo el mecanismo: un miembro (3) de ajuste de dosis, un miembro (4) de accionamiento, para accionar un vástago de pistón durante la dispensación de dosis, comprendiendo el miembro (4) de accionamiento un miembro de accionamiento proximal (4") y un miembro de accionamiento distal (4'), un primer embrague para acoplar de modo liberable el miembro de accionamiento proximal (4") y el miembro de accionamiento distal (4'), medios de resorte (7) para cargar el miembro de accionamiento proximal (4") y el miembro de accionamiento distal (4') en el estado acoplado durante el aj
