1. A method for informing a user of an intoxication state, comprising: Upon receiving an input from the user at a wrist-borne mobile computing device associated with the user, prompting a user to provide a breath sample to a sample receiving module at a first time point; at a processing subsystem in communication with the sample receiving module, receiving a breath sample signal derived from the breath sample; at the processing subsystem, determining a value of a blood alcohol content (BAC) metric from the breath sample signal; at the processing subsystem, generating a predicted temporal profile of the BAC metric for the user over time, based upon the value of the BAC metric and the first time point; and transmitting commands, from the processing subsystem to the wrist-borne mobile computing device, that prompt the wrist-borne mobile computing device to display information from an analysis derived from the predicted temporal profile at a display of the wrist-borne mobile computing device, thus informing the user of the intoxication state.