Your medicine cabinet/drawer/shelf is filled to the brim with boxes of antibiotics that you never finished, or a box of old pain killers you bought after one too many with your mates on Saturday night, right? When was last time you checked the label? Well, most medication loses potency over time or even breaks down into harmful substances and using old medication can result in under-dosing or worse. While medication is usually marked with expiration dates (check the bottom of the box) they may be difficult to read or easy to overlook. A proposed technology may change that: new “self expiring” packaging contains a smart film sandwich that displays a bold universal “do not” symbol across the entire label once the expiration date is passed. But before that’s the norm, look through that shelf and clean out anything that’s past its due date.