text: drug test question? im under 21 and i have to take a drug test in 2 days because im on probation.  on the list of stuff it says it checks for it says alcohol.  will it show up that i have alcohol in my system if i drank exactly a week ago the day i take my drug test? no the alcohol is out of your system from a week ago.  but surprisingly it can be in your system from 2 days ago so be careful.