Abstract: Connection systems for injection devices are disclosed. Also disclosed are injection devices and methods of using the same. A connection system includes a first and second connection assembly and a coupling assembly to secure the same. The first connection assembly connects to a medicament container, and the second connection assembly has a needle movable toward the medicament container. Removable flexible barriers are disposed on the first and second connection assemblies and can be removed once the connection assemblies are coupled together to form an aseptic connection between the two assemblies. The needle can be moved toward the medicament container to pierce a septum on the container to form a fluid communication between the container and the needle.