A dispenser device for dispensing a fluid or powder composition, the dispenser device comprising: a dispenser head (1) that is provided with a dispenser outlet (10) that is formed at the end of a hollow sleeve (3)； an air expeller (20) for generating a flow of air while the device is being actuated, said air expeller including a piston (21) that slides in an air chamber (22) between a rest position and a dispensing position, said air chamber (22) including a cylindrical body in which said piston (21) slides in airtight manner； and a reservoir (30) that contains a single dose of composition, said reservoir (30) including an air inlet (31) that is connected to said air expeller (20), and a composition outlet (32) that is connected to said dispenser outlet (10), said air inlet (31) including a composition retainer member (40) for retaining the composition in the reservoir (30) until the composition is dispensed, and said composition outlet (32) being closed by a closure element (50) that is force fitted in the composition outlet (32) of the reservoir (30)； said device further comprising a mechanical opening system (61, 62) that co-operates with said closure element (50) so as to expel it mechanically from its closed position while the device is being actuated； said device further comprising an indicator (100； 50) that, in the rest position before actuation, is in a first state, and that after actuation passes into a second state, the passage from the first to the second state informing the user that the device has been actuated, said first state being a visible state and said second state being a non-visible state, said device including a pusher element (25) that is secured to said piston (21), and on which the user presses during actuation, said dispenser head (1) including a skirt (5) that is arranged around said air chamber (22), said pusher element (25), in its rest position before actuation, projecting axially out from said skirt (5), and after actuation, being ar
