An injection pen needle having a safety shield system, comprising: a needle hub; a needle mounted in the hub and having an injection end and a non-injection end, wherein the hub has radial walls defining a first recess surrounding the injection end of the needle and a second recess surrounding the non-injection end of the needle to receive a pen-injector; a first shield movable coaxially over the radial wall defining the first recess of the hub and having an aperture in an end wall thereof for passage of the needle, wherein the first shield is movable between a retracted position in which the needle is exposed and a full travel position in which the shield covers the injection end of the needle; and a first elastic member (300, 320) housed between the first shield and the hub, engaging the first shield to hold the first shield in the full travel position, said first elastic member being a clip (300, 320) positioned against the hub and having a tab, characterized in that the system comprises a second shield within the radial wall defining the second recess of the hub having an aperture to permit passage of the non-injection end of the needle into the pen-injector, wherein the second shield is movable within the radial wall defining the second hub recess from a position in which the pen injector is installed in the hub to a full travel position in which the pen injector is removed from the hub and the second shield covers the non-injection end of the needle; and a second elastic member housed between the second shield and the hub, engaging the second shield to hold the second shield in its full travel position, thereby preventing the shield from further movement in relation to the non-injection end of the needle and the hub; wherein said tab of the first elastic member engages aligned slots in both the radial wall of the hub and the radial wall of the first shield to form a locked position therebetween when the first shield is in its full travel position. a needle hub; a needle mounted in the hub and having an injection end and a non-injection end, wherein the hub has radial walls defining a first recess surrounding the injection end of the needle and a second recess surrounding the non-injection end of the needle to receive a pen-injector; a first shield movable coaxially over the radial wall defining the first recess of the hub and having an aperture in an end wall thereof for passage of the needle, wherein the first shield is movable between a retracted position in which the needle is exposed and a full travel position in which the shield covers the injection end of the needle; and a first elastic member (300, 320) housed between the first shield and the hub, engaging the first shield to hold the first shield in the full travel position, said first elastic member being a clip (300, 320) positioned against the hub and having a tab, characterized in that the system comprises a second shield within the radial wall defining the second recess of the hub having an aperture to permit passage of the non-injection end of the needle into the pen-injector, wherein the second shield is movable within the radial wall defining the second hub recess from a position in which the pen injector is installed in the hub to a full travel position in which the pen injector is removed from the hub and the second shield covers the non-injection end of the needle; and a second elastic member housed between the second shield and the hub, engaging the second shield to hold the second shield in its full travel position, thereby preventing the shield from further movement in relation to the non-injection end of the needle and the hub; wherein said tab of the first elastic member engages aligned slots in both the radial wall of the hub and the radial wall of the first shield to form a locked position therebetween when the first shield is in its full travel position.