A medical delivery device is disclosed including a rod element, a dosage member and a lock mechanism. The rod element has a stem and the dosage member includes a delivery orifice and a chamber body. The stem of the rod element extends into the chamber body and the delivery orifice is arranged adjacent to a proximal end of the stem. In a dosing status, the rod element is movable along its longitudinal axis relative to the delivery orifice, wherein a dosage chamber is formed within the chamber body between the stem and the delivery orifice such that the dosage chamber increases when the rod element moves away from the delivery orifice. The lock mechanism is adapted to change the medical delivery device from a lock status to a dosing status, wherein, in the lock status moving the rod element along its longitudinal axis relative to the delivery orifice is prevented.