A drive assembly (3) for a medication delivery device (1) is provided which is switchable from an operational state to a resetting state and which comprises: -a housing (13) having a proximal end (8) and a distal end (15), -a drive member (20) adapted to be rotated with respect to the housing (13), and -a stop member (26) adapted to prevent rotational movement of the drive member (20) in a first direction with respect to the housing (13) and to permit rotational movement of the drive member (20) in a second direction with respect to the housing (13), the second direction being opposite to the first direction. In the operational state of the drive assembly (3) the stop member (26) is held in engagement with the drive member (20), and for switching into the resetting state of the drive assembly (3) the stop member (26) is enabled to disengage from the drive member (20) caused by gravity due to the weight of the stop member (26). Moreover, in the operational state of the drive assembly (3) the drive member (20) may beheld in engagement with a rotation member (21), and for switching into the resetting state of the drive assembly (3) the drive member (20) may be enabled to disengage from the rotation member (21) caused by gravity due to the weight of the drive member (20).Linvention porte sur un ensemble dentraînement pour un dispositif dadministration de médicaments et sur un dispositif dadministration de médicaments. Linvention porte sur un ensemble dentraînement (3) pour un dispositif (1) dadministration de médicaments qui peut passer dun état fonctionnel à un état de réinitialisation, et qui comprend : - un boîtier (13) ayant une extrémité proximale (8) et une extrémité distale (15), - un élément dentraînement (20) conçu pour tourner par rapport au boîtier (13), et - un élément de butée (26) conçu pour empêcher un mouvement rotatif de lélément dentraînement (20) dans une première direction par rapport au boîtier (13) et permettre un mouvement rotatif de lélément dent
