I've seen the study, but I don't feel like hunting around for it. A single shot of 200mg of Deca shut down all participants for around 12 weeks.
AR cited 100 mg in the profile (which included a rather cloudly chart), but didn't clearly reference the source. You'd have to sift through his references for validity.
http://www.steroid.com/Deca-Durabolin.php
And you can't always tell if you're shut down, though I assure you that a blood test would have shown 100% suppression.
Very true, especially when it occurs quickly, as in the case of aas use.
Some guys can function just fine for a while so long as they have some sort of androgen in their system, even if it isn't test.
I hate to beat a dead horse, but 'true' again. The negative feedback loop still registers androgens as valid sex hormones. Contrarywise, some guys get complete ED from running Deca only, so we see very specific individual differences...it's a paradox.