A modular gas-actuated retractable needle assembly, syringes for engagement with the modular gas-actuated retractable needle assembly, and kits comprising same are provided. In some embodiments, the syringe has a distal swedge to facilitate engagement of syringes of a plurality of different sizes with a single modular gas-actuated retractable needle assembly. Methods of using the modular gas-actuated retractable needle assembly or a syringe assembly having a modular gas-actuated retractable needle assembly are provided.
