When you inject a lot of testosterone, your body decides it can't use it all.This triggers 2 things. One, it converts the excess to estrogen. Excess estrogen can give you all the negative side effects you've heard of about taking testosterone. Hair loss/acne/bitch tits, emotional problems, etc.And two, if you're taking too much test for too long, your brain tells your balls to stop producing testosterone. That's why your balls shut down and start to shrink.Smart people will run a cycle of testosterone, and take arimidex, which is a great estrogen blocker. After their cycle, they will take HCG. (One of the ones Chael got caught for). HCG super kick starts your natural production again, makes your balls swell to twice their original size before they shrunk (for those of you who are into that)Clomid is supposed to be the best of both worlds. You can take it the whole time you run a cycle, and it blocks estrogen as well as telling your balls to keep producing test even though your body is overloaded with it. If arimidex is a black belt in estrogen blocking, and HCG is a black belt in kickstarting your natural production, then Clomid is a brown belt in both.As I stated, the advantage is that you can take it the whole time you run a cycle, and it perform both functions. Maybe not as good as the ideal choices, but it is ideal for guys wanting to beat PED tests. Because after you stop a cycle, you'd need to take HCG for at least a month to get your balls back to normal production. And then it'll show up on a drug test for 90 days after that. So you're looking at 4 months off of steroids before you will be clean.Whereas, if you run clomid the whole time, and stop a month before your cycle stops (because its detectable for about 60 days, and take testosterone propionate (which is non detectable after 3 weeks) you literally can stop a cycle, and 3-4 weeks later, piss completely clean. I've also heard that repeatedly that for big $, you can get synthetic testosterone that is completely undetectable to any piss or blood test, as far as showing up as synthetic. My guess would be, that testosterone is coming directly from other humans bodies, dead or alive. Not really sure.My guess is, Brock and Jon, cut it too close by not stopping the clomid soon enough. By the way, PED testing is not an exact science. Chael himself said recently in an interview "I didn't comment on my positive test, because I knew there was another test still out there. And I knew what should be on it, based on them hitting me with a surprise test, but turns out none of it showed up".