Cheating has changed over the years; some time ago cheaters preferred to get clean human urine and keep it fresh and warm until they could attempt to pass it off as their own. We don’t see nearly as much of that today; more commonly cheaters “go to” today is synthetic urine.
You can purchase a wide variety of synthetic urine, all manufacturers claiming theirs is guaranteed! I must admit that some synthetics are quite good at fooling the labs, we know this because we have sent in many specimens to the lab knowing it was synthetic and the labs reported it as negative.
A donor came in and gave one of our collectors an out-of-range specimen. As our collector was explaining to the donor that he could not accept the sample, the donor asked, “Is there anything you can do to help me pass?”