This syringe (1) comprises an elongate hollow body (3) forming a reservoir intended to contain a substance to be injected, the body (3) comprising a tip intended to receive a connection device and an opening (32) located at the opposite side of the body (3) relative to the tip, a piston mounted sliding in the body (3) and movable in translation along a longitudinal axis (X3) of the syringe between a retracted position, in which the piston is in abutment at the tip side, and an extended position, in which the piston is in abutment at the opening side (32), gripping members (34, 36) provided on the body (3), and a gripping member (50) provided at an opposite end of the piston relative to a head of the piston. The gripping members (34, 36) provided on the body (3) comprise bearing areas (34a, 36a) for fingers of a user, oriented towards the gripping member (50) of the piston, and the gripping member (50) of the piston comprises at least one bearing area for fingers of the user, located facing the gripping members (34, 36) provided on the body (3). The piston (5) is formed from a single piece made from a material having a Young's modulus greater than 3000 MPa and the piston (5) has no elastic area between the gripping member (50) of same and the substance to be injected.