The needless vial assemblies described herein allow for the access to the contents of a vial, such as a medication, using a syringe without a needle. In some designs, the vial includes a vial neck, which is itself a syringe interface. The vial assemblies also include a cap with a plug, which can be used to seal the vial assembly. The present disclosure further provides methods of filling a vial assembly and methods of filling a syringe using the vial assemblies described herein.
