The invention relates to a system (1) for providing an injection, comprising a first container (3), which is formed with a first cavity (5) and has a rigid outer wall (7) and two ends. A movable plug (11) is provided on one side of the first cavity (5), said plug sealingly closing the first cavity and being movable within the first container (3). The system also comprises a second container (21) which encloses a second cavity (23). One container contains a first substance, and the other container contains a second substance. The invention is characterized in that the second container (21) comprises a wall (35) which is elastic in at least some regions, and the second container thus encloses a variable volume the second container (21) is designed such that a pressure can be built up in the interior of the second container (21) by means of the wall which is elastic in at least some regions and the second container (21) is a tube.
