Medicated module with lockable needle guard

A medicated module (4) for an injection system to co-deliver at least two medicaments is disclosed where a primary delivery device (7) containing a primary medicament accepts a medicated module (4) containing a single dose of a secondary medicament and where both medicaments are delivered through a single hollow needle (3). The medicated module (4) is configured so that it will first deliver both the primary and secondary medicaments and then, if needed, a dose(s) of additional primary medicament. The module (4) also contains a needle guard (22) that locks the first dose delivery, but can be manually overridden by a user to perform a second or subsequent injection of primary medicament.