The present invention relates to a device (1) for automatic injection of a product (3) into an injection site (4), the product (3) being carried by a container (5) having an open proximal end and a substantially closed distal end and having a reservoir defined therebetween, and a needle (6) provided at the distal end and in fluid communication with the reservoir to provide an outlet port for the product (3) from the container, and a piston (7) provided in the container and movable with respect with the container, the movement of the piston causing the product to be expelled from the container through the needle, characterized in that the device comprises:- a housing (8) for the container, the container being movable relative to the housing between an initial position, in which a tip of the needle does not extend beyond a distal end of the housing and in which the container is in one of a passive state and an active state, to an insertion position, distally spaced relative to the initial position and in which the tip of the needle extends beyond the distal end of the housing, movement of the container out of its first position being prevented when the container is in its passive state, and being permitted when the container is in its active state, and- a safety shield (10) coupled to the housing (8) for movement between a first position and a second position in which the tip of the needle does not extend beyond a distal end of the shield, movement of the shield (10) out of its first position placing the container (5) in its active state, the shield (10) being movable to its second position when the container (5) is in the insertion position, the shield (10) being secured against proximal movement when in the second position, and- a needle shield (2) coupled with said housing and covering the needle prior to use of said device, removal of said needle shield being with limited or no rotation of said needle shield.
