what is the 'shelf life' of vicodin 500mg tablets? i've been having a lot of back pain lately and i looked through my medicine cabinet and came across an old prescription of mine from february of 2007. i've been researching if these are still good to take and i came across a study on prescription saying that manufacturers are forced to put an expiration date of exactly a year from the filling of the prescription, however they are good to take for longer after the expiration. so i'm wondering if it really is okay for me to take these or if i should just pitch them..