A needle housing (115) having a distal end which is removably connectable to a source of injectable fluid (110) and a proximal end (80) for contacting a patient, as well as to an injection apparatus comprising the needle housing. The needle housing comprises (a) a hollow needle through which the injectable fluid is deliverable to the patient, the needle having a proximal end for insertion into body tissue of the patient, and (b) a chamber (75) having an open proximal end, the chamber surrounding at least part of the needle and extending proximally beyond the proximal end of the needle to the open proximal end. The open proximal end of the chamber is deformable and is moveable relative to the needle from a position in which the chamber extends proximally beyond the proximal end of the needle to a position in which the proximal end of the needle extends proximally through the open proximal end of the chamber.