A drug dispenser assembly comprising: a drug dispenser for dispensing a drug in a dispense event; and a skinprint analyser configured to receive a skinprint, preferably a fingerprint, of a user. The skinprint analyser is further configured: to perform a verification test regarding the identity of the skinprint; to conduct a chemical analysis for the presence of a metabolite in the skinprint; and to produce data indicative of results of the verification test and the chemical analysis. The drug dispenser assembly further comprises an actuator configured to actuate a dispense event in the event that the results of one or both of the verification test and the chemical analysis meet one or more predetermined conditions.