Abstract: The object of the present invention is a syringe the essential function of which is to avoid that it is used again after having been used once. This is achieved by means of a piston joined to a pusher which inside the cylinder of the syringe does not reach the end, as there has to be provided a second pusher situated preferably in the centerof same which separates the piston of the pusher resting the piston at the interior end of the syringe, and the pusher free. In order to avoid that the end joined to the needle be manipulated, there can be provided a fixed needle, or either a channel between the cylinder and the corkscrew needle, impossible to be manipulated.