A drug delivery device comprising: a body and a movable component arranged inside the body; a dosage selection and injection mechanism (13, 20) setting the position of the movable component inside the body depending on a selected dosage; a non-contact sensor configured to output signals indicative of the position of the movable component inside the body; and a processor configured to receive the signals output from the non-contact sensor and to determine based on the signals whether the movable component is either in an initial position inside the body corresponding to no selected dosage or in a selected dosage position, wherein upon determining that the movable component has changed its position back from the selected dosage position to the initial position, the processor is configured to cause an indication to be output which informs a user regarding a dwell time of the drug delivery device; wherein the processor is further configured to cause an indication to be output which informs a user of the end of the dwell time of the drug delivery device; wherein the non-contact sensor is a capacitive sensor and wherein the body, the movable component and the dosage selection and injection mechanism form at least a part of a dielectric layer of the capacitive sensor; and wherein the processor is further configured to measure the capacitance of the capacitive sensor when no dosage is selected and the movable component is in the initial position inside the body, to store the measured capacitance as a reference value, to detect a capacitance change when a dosage is selected, to detect a further capacitance change due to an injection and to determine the end of the injection and beginning of the dwell time when the measured capacitance correlates with the reference value. a body and a movable component arranged inside the body; a dosage selection and injection mechanism (13, 20) setting the position of the movable component inside the body depending on a selected dosage; a non-contact sensor configured to output signals indicative of the position of the movable component inside the body; and a processor configured to receive the signals output from the non-contact sensor and to determine based on the signals whether the movable component is either in an initial position inside the body corresponding to no selected dosage or in a selected dosage position, wherein upon determining that the movable component has changed its position back from the selected dosage position to the initial position, the processor is configured to cause an indication to be output which informs a user regarding a dwell time of the drug delivery device; wherein the processor is further configured to cause an indication to be output which informs a user of the end of the dwell time of the drug delivery device; wherein the non-contact sensor is a capacitive sensor and wherein the body, the movable component and the dosage selection and injection mechanism form at least a part of a dielectric layer of the capacitive sensor; and wherein the processor is further configured to measure the capacitance of the capacitive sensor when no dosage is selected and the movable component is in the initial position inside the body, to store the measured capacitance as a reference value, to detect a capacitance change when a dosage is selected, to detect a further capacitance change due to an injection and to determine the end of the injection and beginning of the dwell time when the measured capacitance correlates with the reference value.