This syringe (1) comprises: - a syringe body (2), intended to receive a product for injection； - gripping wings (4), arranged at one end (21) of the syringe body (2)； - a piston rod (5), mounted so as to be able to slide inside the syringe body (2), - a stop (6), arranged at a first end (50) of the piston rod (5), and having an end-of-travel position inside the syringe body (2)； - a pusher (7), arranged at a second end (51) of the piston rod (5)； the syringe (1) being remarkable in that the pusher (7) has a mass greater than or equal to a threshold value beyond which the syringe (1) has a centre of gravity situated outside the syringe body (2) when the stop (6) is in the end-of-travel position.
