Many “Interferon Rangers” recommend not using the syringe that comes with your interferon prescription, for the actual injection. Use that one to mix the interferon powder, and buy a box of ? cc Microfine IV 29 gauge syringes to use for the injection. The needle that comes with your interferon is a fairly large gauge and inserting it through the rubber stopper of the interferon vial dulls it a little. Using a smaller gauge needle will make the injection more comfortable, and using a separate needle to mix the diluent with the powder will keep your injection needle sharper.