The present invention relates to medical delivery devices for administering a dose of a drug into the body of a subject user and incorporating a time lapse indicator which is configured for indicating after administration that a dose of the drug actually has been administered and for maintaining this indication until lapse of a pre-defined time interval. The time lapse indicator disclosed is based on a pressure sensitive substance which exhibits a change in a visual property in response to an action associated with administering a dose and wherein the pressure sensitive substance exhibits a further change in a visual property after lapse of a pre-defined time interval subsequent to said action.
