A drug delivery system for injecting a medicament, the system comprising: a housing; a container at least partially positioned within the housing, the container configured to contain a medicament; a needle actuator assembly received within the housing, the needle actuator assembly comprising: a needle actuator body having a guide surface, the needle actuator body moveable between a pre-use position, a use position, and a post-use position, a needle shuttle having a cam surface, the needle shuttle moveable along a vertical axis between retracted position and an extended position, the needle shuttle configured to move between the first and second position through engagement between the guide surface of the needle actuator body and the cam surface of the needle shuttle, a needle received by the needle shuttle, and a button actuator at least partially received by the housing, wherein movement of the button actuator is configured to move the needle actuator body from the pre-use position to the post-use position, wherein movement of the needle actuator body from the pre-use position to the use position is configured to cause movement of the needle shuttle from the retracted position to the extended position, wherein movement of the needle actuator body from the use position to the post-use position is configured to cause movement of the needle shuttle from the extended position to the retracted position, and wherein, when the needle actuator body is in the use position, the container is in fluid communication with the needle via a tube in order to deliver the medicament from the container, through the needle, and to the user characterized in that, when the needle actuator body is in the post-use position with the guide surface of the needle actuator body disengaged from the cam surface of the needle shuttle, a biasing member of the needle shuttle biases the needle shuttle toward the extended position in a direction substantially parallel with the vertical axis. a housing; a container at least partially positioned within the housing, the container configured to contain a medicament; a needle actuator assembly received within the housing, the needle actuator assembly comprising: a needle actuator body having a guide surface, the needle actuator body moveable between a pre-use position, a use position, and a post-use position, a needle shuttle having a cam surface, the needle shuttle moveable along a vertical axis between retracted position and an extended position, the needle shuttle configured to move between the first and second position through engagement between the guide surface of the needle actuator body and the cam surface of the needle shuttle, a needle received by the needle shuttle, and a button actuator at least partially received by the housing, wherein movement of the button actuator is configured to move the needle actuator body from the pre-use position to the post-use position, wherein movement of the needle actuator body from the pre-use position to the use position is configured to cause movement of the needle shuttle from the retracted position to the extended position, wherein movement of the needle actuator body from the use position to the post-use position is configured to cause movement of the needle shuttle from the extended position to the retracted position, and wherein, when the needle actuator body is in the use position, the container is in fluid communication with the needle via a tube in order to deliver the medicament from the container, through the needle, and to the user characterized in that, when the needle actuator body is in the post-use position with the guide surface of the needle actuator body disengaged from the cam surface of the needle shuttle, a biasing member of the needle shuttle biases the needle shuttle toward the extended position in a direction substantially parallel with the vertical axis. a needle actuator body having a guide surface, the needle actuator body moveable between a pre-use position, a use position, and a post-use position, a needle shuttle having a cam surface, the needle shuttle moveable along a vertical axis between retracted position and an extended position, the needle shuttle configured to move between the first and second position through engagement between the guide surface of the needle actuator body and the cam surface of the needle shuttle, a needle received by the needle shuttle, and a button actuator at least partially received by the housing, wherein movement of the button actuator is configured to move the needle actuator body from the pre-use position to the post-use position, wherein movement of the needle actuator body from the pre-use position to the use position is configured to cause movement of the needle shuttle from the retracted position to the extended position, wherein movement of the needle actuator body from the use position to the post-use position is configured to cause movement of the needle shuttle from the extended position to the retracted position, and wherein, when the needle actuator body is in the use position, the container is in fluid communication with the needle via a tube in order to deliver the medicament from the container, through the needle, and to the user characterized in that, when the needle actuator body is in the post-use position with the guide surface of the needle actuator body disengaged from the cam surface of the needle shuttle, a biasing member of the needle shuttle biases the needle shuttle toward the extended position in a direction substantially parallel with the vertical axis.