The present invention relates to a cartridge for a drug delivery device comprising of a body of substantially cylindrical shape, a piston slidably disposed in the body along two opposite axial directions, along a distal and along a proximal direction, and at least one friction means operably engaged with the piston to generate a pre-defined friction force between the piston and an inside wall of the body, when the piston is displaced relative to the body, wherein in response to an axial displacement of the piston relative to the body in distal direction and in proximal direction, the at least one friction means is adapted to generate respective proximal and distal friction forces that are different in magnitude.