The present disclosure concerns a needleless injection device including a body forming a housing, a gas generator, a tubular reservoir which contains an active ingredient to be injected, and a generally T-shaped elastically deformable membrane. The membrane includes a tubular portion which extends axially in the reservoir and is designed to lie axially in the reservoir under the effect of the pressure generated by the gas generator. A nozzle for injecting the active ingredient is arranged at the lower end of the reservoir. The device further includes a sock which wraps the tubular portion of the membrane, at least partially. The sock is adapted to limit the friction between the tubular portion of the membrane and the reservoir.
