A syringe comprising: - an elongate hollow body forming a reservoir intended to contain a substance to be injected, the body comprising a tip intended to receive a connection device, and an opening located at the opposite end of the body relative to the tip, - a piston mounted slidably in the body and movable in translation along a longitudinal axis of the syringe between a retracted position, in which the piston is in abutment at the tip, and an extended position, in which the piston is in abutment at the opening, - gripping members (34, 36) provided on the body, and a gripping member provided at an opposite end of the piston relative to a head of the piston, the gripping members (34, 36) provided on the body comprising bearing zones (34a, 36a) for fingers (In, M, P) of a user, which bearing zones (34a, 36a) are oriented toward the gripping member of the piston, the gripping member of the piston comprising at least one bearing zone for fingers (In, M, P) of the user, which bearing zone is located facing the gripping members (34, 36) provided on the body, characterized in that the piston is formed as a single piece made from a material having a Young's modulus greater than 3000 MPa, and in that the piston has no elastic zone between its gripping member and the substance to be injected. - an elongate hollow body forming a reservoir intended to contain a substance to be injected, the body comprising a tip intended to receive a connection device, and an opening located at the opposite end of the body relative to the tip, - a piston mounted slidably in the body and movable in translation along a longitudinal axis of the syringe between a retracted position, in which the piston is in abutment at the tip, and an extended position, in which the piston is in abutment at the opening, - gripping members (34, 36) provided on the body, and a gripping member provided at an opposite end of the piston relative to a head of the piston, the gripping members (34, 36) provided on the body comprising bearing zones (34a, 36a) for fingers (In, M, P) of a user, which bearing zones (34a, 36a) are oriented toward the gripping member of the piston, the gripping member of the piston comprising at least one bearing zone for fingers (In, M, P) of the user, which bearing zone is located facing the gripping members (34, 36) provided on the body, characterized in that the piston is formed as a single piece made from a material having a Young's modulus greater than 3000 MPa, and in that the piston has no elastic zone between its gripping member and the substance to be injected. the gripping members (34, 36) provided on the body comprising bearing zones (34a, 36a) for fingers (In, M, P) of a user, which bearing zones (34a, 36a) are oriented toward the gripping member of the piston, the gripping member of the piston comprising at least one bearing zone for fingers (In, M, P) of the user, which bearing zone is located facing the gripping members (34, 36) provided on the body, characterized in that the piston is formed as a single piece made from a material having a Young's modulus greater than 3000 MPa, and in that the piston has no elastic zone between its gripping member and the substance to be injected.