Baseball seems to have largely eliminated doping.
Ok, that example is confined to a small population of athletes in the U.S., so an imperfect example.
Cycling appears to be getting doping under control. That's a good analogue to running, except there are few elite African cyclists.
So there is evidence that, once the affect community forces the authorities are forced to address the issue, doping gets seriously squeezed.
Outlaws always come up with clever ways to outsmart the law--Wall St being a prime example--but society still strives for fairness as a measure of justice.