An attachment for an injection pen or syringe, the attachment being attachable to the needle or needle end of an injector pen (7) or syringe, the attachment comprising a circumferential array of inwardly pointing flexible fingers (9) configured such that when the flexible finger tips are pressed against the injection site the flexible fingers are capable of flexing axially and inwardly to promote the gathering of a pucker of subcutaneous tissue in the vicinity of a needle insertion point.