The invention provides an injector comprising a body and a container. The body has an injection opening and including a drive mechanism which can be actuated to move the container within the body and inject medication from the container through the injection opening. The container comprises an outlet and includes an injection needle releasably coupled thereto. The injection needle comprises a hub and a needle. The hub extends along a first axis between a connecting end and a needle end. The connection end comprises connection means for connecting to the container and the needle connecting to the hub at a needle end. The needle extends from the hub along the first axis to an injection end. The injection needle comprises a channel extending from the connection end of the hub to the injection end of the needle. The hub comprises at least one reference shoulder extending radially from the hub and directed towards the injection end. The injection needle further comprises a needle shield, the needle shield releasably coupled to the needle hub and substantially covering the needle. The body further includes a body stop, the body stop comprises a shoulder extending radially inwardly from the body to define an aperture though which the needle shield, but not the reference shoulder can pass. The body stop being configured to contact the at least one reference shoulder extending from the hub to limit the distance the injection end of the needle extends out of the injection opening.
