Since I cannot post on BB.com, just providing a response to my friend (hopefully he sees it):
There is nothing out of the ordinary that can induce rapid tachyphylaxis in Enhanced. There are no releasing agents or cumulatively sympatholytic agents in the formula. I am not denying his account by any means, but I'm just at a loss for what could be causing it. The caffeine alone would be at over 425mg at 3.5 scoops. I also am in awe at his ability to tolerate high doses of nitrates...3.5 scoops would have me in a mind-numbing headache for hours!
I guess I should obligatorily ask, are you using any other supplements? For instance, if you're using PEA/PEA derivatives on the side at other times of day, they can pretty much limit the effects of any other stimulant, including caffeine. Also, any other outside agmatine use? Very high doses of agmatine can build up in the CNS and exert adrenergic effects on postsynaptic nerve terminals.
Sorry if this post seems way out of context, I'm just hoping my friend sees it. Such is the nature of being banned on BB.com