A single use lancet device having a housing, with an open interior and an access opening defined therein, a lancet, with a body and a piercing tip, and disposed in the open interior of the housing so as to move between a cocked orientation and a piercing orientation, a driving assembly structured to move the lancet into the piercing orientation, and a restrictor assembly having a shoulder element and a restrictor panel operatively associated with the lancet and the housing and structured to pass over the restrictor panel upon the lancet moving from its cocked orientation to its piercing orientation, and to abut the restrictor panel upon attempted movement of the lancet back into its cocked orientation after movement into the piercing orientation, thereby preventing the lancet from moving back into the cocked orientation and preventing re-use of a contaminated piercing tip.