The win must be over someone who tested positive or was on TRT for that particular fight.
I'm guessing Anderson Silva with 7 wins: Sonnen (twice), Hendo, Vitor, Griffin, Bonnar, Irvin.
Sidenote: Anderson beat the 3 guys Bisping complains about losing to.
Griffin was never on a PED. He took Xanax. And he didn't start TRT until his last couple fights I thought. 
Also vitor was on TRT when he fought Anderson if I remember correctly
^wasnt*
Sorry for double post I'm on iPhone
with damn near every fighter on peds, it doesnt really matter
GayGuardMooseSaucy - Griffin was never on a PED. He took Xanax. And he didn't start TRT until his last couple fights I thought.
Well it was a banned substance. Including non-steroid banned substances, Anderson's record is seven. Against PED/TRT junkies, it's six.
A deserving metric to measure his GOATness.
Ew0k187 - Also vitor was on TRT when he fought Anderson if I remember correctly
However, Belfort revealed in an interview to UOL that he was already on the testosterone replacement therapy when he fought Silva, back in 2011.
http://www.mmafighting.com/2013/10/31/5050318/vitor-belfort-would-accept-to-stop-trt-for-shot-at-the-title
Corn Nuts -Despite not having a TUE.....Ew0k187 - Also vitor was on TRT when he fought Anderson if I remember correctly
However, Belfort revealed in an interview to UOL that he was already on the testosterone replacement therapy when he fought Silva, back in 2011.
http://www.mmafighting.com/2013/10/31/5050318/vitor-belfort-would-accept-to-stop-trt-for-shot-at-the-title
I guess the winner is Anderson with 6 (if you don't count Griffin).
Anderson is a one man war on drugs.
Fedor must have gone through a fair few.
EckY - Fedor must have gone through a fair few.Based on the thread title I'll go with zero
EckY - Fedor must have gone through a fair few.
I purposely excluded PRIDE since it encouraged PED use. Hell, Alexander Otska probably has 15 wins over PED fighters.