I wouldn't take much of anything Rich Piana said too seriously. I don't get the cult like following he had(not at all saying this is you OP) . He was praised for his openness and honesty, and while those are important traits, surely there are other important factors to consider when judging someone. He seemingly based much of his advice off anecdotes, bro science, and intuition. I think of things like his "8 hour arm workout" and just shake my head. I'm not a hater, and he had a great physique before he went crazy with the Synthol, but I just don't see myself taking advice from him when there are so many other, far better sources. As for the test concentration, I've had test at around 450mg/ml of Cyp and Enanthate, and had zero pip. Things like specific esters, carrier oils, solvents etc and your personal tolerances to those things, are likely to prove as important as concentration per ml