I began smoking marijuana regularly in 2002. I have taken, and passed, multiple drug screens, including for Government, Top Secret Clearance-level, jobs. In mor

I began smoking marijuana regularly in 2002. I have taken, and passed, multiple drug screens, including for Government, Top Secret Clearance-level, jobs. In more socially-conservative areas, which I lived, you will see more IT jobs requiring drug tests, including in the private sector (Hewlett Packard, Hynix, and Intel screened, to name a few). Since nobody has on-site testing facilities, You usually get a 2-3 day window to attend a third-party lab and let them take a sample, which gives you ample time to procure the items you need to pass them. In the event of a random (or targeted) drug screen, you will still have an hour or two, likely giving you enough time to go home and get your pre-bought equipment. Urine tests are usually easy to pass, as it's likely an invasion of your privacy as a non-felon to watch you urinate, therefore, it is a trivial matter to have synthetic urine (bottle warmed in your inner-thigh/groin to body temperature) ready to squirt into the cup, as well as into the toilet. If I recall, it was about $25 to purchase a bottle. Hair tests required you to purchase $30 bottles of special shampoo that would strip away anything (leaving your hair feeling like straw), provided you follow the directions on the box, which was to scrub like crazy for 15 minutes. You'd get a good 3-4 hours of clean hair to attend the lab, which is more than enough time for most people. I now work at a (incubating) canadian medical marijuana startup, so I no longer worry about such things, but I'm sure I'll be telling the grandkids about the measures people took during prohibition eventually.