The method worked flawlessly, I did not get the results yet but I know ill pass, my only concern was the temp which made it to 94 on the temp strip. So in my opinion for a PRE-EMPLOYMENT DRUG SCREEN substitution is the way to go. It was so easy and much easier to do than spending money on test strips, vitamins, & creatine pills. All you need is a 2oz bottle and clean urine.