It all depends on the federation sanctioning the show. Some fedeartions are 2 years drug free. Some are three. Some are 6 or sven years. Some only polygraph the top three. Some polygraph everybody. Some do urinalysis which you front the money for (pass and you get some or all back). Some don't make you piss. It all depends.
Some ban gear, HGH, diuretics, and "any other illicit substance that may promote muscle growth or enhance physical condition". Others take it as far to ban prohormones. Other go even further to ban Thermogenics.
I say fuck it man. Jack your self up as freaky as possible and take on all comers. If you place enough restrictions on people everyone could win the "Olympia" in their respective federation. I would much rather qualify nationally in an untested or minimally tested show than to be Mr. "Olympia" in the OCNBBFLWDTGSWDEBWHBHSTPF(Overly Conservative Natural BodyBuilders For Life Who Don't Take Gear or Supplements Who Don't Eat Broccolli Who Have Brown Hair and Shave Their Pubes Federation).