Medical device inserters and processes of inserting and using medical devices

A medical device inserter, comprising:

• a bellows, a sheath, a removable distal cap defining a sterile environment with a medical device and an inserter sharp housed within the sterile environment, and a carriage shaped with a recess, the recess receiving an on body housing that includes sensor electronics for the medical device, wherein the medical device is an analyte sensor, wherein the bellows is compressible to advance the medical device through a skin layer, and a coil spring set within the bellows is adapted to provide a force for withdrawing the inserter sharp after advancing the medical device through the skin layer, wherein a proximal extent of the bellows provides an actuation portion of the medical device inserter, and further wherein the bellows provides the actuation portion of the medical device inserter such that a manual force applied to the actuation portion causes a compression of the coil spring set within the bellows and a downward force to be applied to the carriage.