Disposable double pointed injection needle, and an insulin injection system comprising a disposable double pointed injection needle

A disposable double pointed injection needle has a needle hub to which a thin needle cannula is permanently fasten and which needle hub can be mounted on to a syringe comprising a dose setting and injection mechanism and a cartridge containing a liquid medicine to be injected subcutaneously into a human body. The needle hub is provided with a safety shield guided on the outside surface of the needle hub. The safety shield is urged in a direction away from the needle hub by a spring located between the needle hub and the safety shield. The safety shield has a number of protrusions guided in guiding tracks on the outside surface of the needle hub. The guiding tracks are designed such that the safety shield during injection is moved towards the needle hub, and after injection is moved away from the needle hub by the spring and locked in an irreversible position where the safety shield covers the needle cannula and prevents accidental needle stick injuries.