A pre-slit injection site includes a housing with a flow path therethrough. A first end of the housing carries a pre-slit septum. A second end of the housing carries a coupling component to adapt the site to standard vials. The coupling component, a vial adapter, includes an adapter spike with openings allowing for the drainage of fluid in the vial through the spike and into the injection site. The vial adapter is provided with a skirt housing unit which protects the adapter spike in manufacturing and use. The skirt housing unit also provides features to lockingly engage the adapter with injection site to standard vials, despite dimensional variations in vial closures. Another embodiment of the coupling component is a spike having a barb feature capable of insertion into a standard vial or port and resisting disengagement.A blunt cannula is usable with the injection site combined with the coupling components.