I have done 12 contests, both natural and anything goes. In the natural contests, it is normally 3 yrs. since last use to qualify. All top 5 competitors in each class are tested, some use lie detector tests, and the top winners and overall winners are urine tested.
At the beginning of a few of the natural tested shows I have done, after weigh in, and assignment of numbers, they will call a few of the numbers to be tested right away.
I was tested twice..this by the way you have to pay for also!