Well I don't exactly, but through deduction I have a good idea they do .Let me explain. One thing all the pros say and is never denied, they are all infertile. I have four children and I was doing what I consider large doses when each of them were conceived over 1 grm.test and 100mgs.anadrol for my first(both pharmaceutical grade.goldmine test and Syntex anadrol). I only had sex with her one time.With my last one I was preparing for a show and it was 7 yrs later so my dosages were higher and had been on the whole time.Its been 15yrs since then and my dosages are higher and I'm still fertile.This is not scientific but unless I'm special, guys are using huge dosages.I never use any kind of pct.