I'm not sure they do. Lamont Peterson made a comeback after he was caught. Mosley and all the rest came back from being found out about it. It doesn't seem like the promoters give a damn as long as they're making money. It makes me think maybe they know all the top fighters are on it.
I dont think the commisioners of any professional sport really goes out of its way to make certain the highest standards in testing are being implemented. Bud Selig of MLB turned a blind eye to the homerun circus that was happeing in baseball during the 90's, there's no question he knew the players were juiced to to the gills when all of a sudden hitting 50 homers was common place for the top HR hitters in the league and you had little guys hitting 30+. Only reason Baseball implemented the drug testing they have now is because the federal government got involved in investigating BALCO! If pro sports in general dont give a damn, much less the most corrupt sport of them all, boxing.
Not in America. Americans love their cheats and drug users for some reason. I guess succeeding by using PED's or using loaded gloves is the American way. Unlike Europeans who get by on talent alone.
Even in the olympics they allow them back in. But that is when they have been found out, speculation is rife in all types of sport... Look at strong men competitions you cant tell me they dont Roid up lol