A feedback mechanism for an injection device that is configured to deliver a medicament to a user is described. The feedback mechanism comprises a piston and a fluid chamber, and the piston is adapted to move into the fluid chamber during use of the injection device. The feedback mechanism also has a damper that is arranged to damp movement of the piston, and an indicator that is arranged to provide feedback to the user after the piston has moved a pre-determined distance into the fluid chamber.