AZ does the most expensive hair testing ever. It goes back 90 days to 6 months and any ILLEGAL drug use will get detected. If you smoke more than one joint a month, the level will be too high and you will fail. It also measures every drug you take. So, if you like to double up on Rx painkillers, it will show that too. They also look at alcohol use. You cannot beat this test, not with bleaching or washing in special shampoo. If you shave all the hair off your body, they will draw your blood and get the same thing. On another note: once you get with AZ, you are going to need all the meds whether legal or not that you can possible get just to deal with the bullshit.