You simplify it too much, mate. Your organism isn’t so smart to keep things always that way so you can be happy - it wants to survive and live as long as possible first, some biochemical reactions and some organs are still primitive and often require pharmacological intervention. By injecting TEST your body’s hormonal concentrations and behavior will never be close to natural because of, e.g. different manner of secretion (pulsative vs few times a week). How your body could be adapted to more or less exacerbated spikes of TEST in your blood? No way, it won’t happen. Your liver function, renal excretion, body fat, sleep time, mental status change, and so on. HPTA was regulating things well enough, you’ve “messed it” enough by injecting TEST, now you have to deal with it, often with necessity of polytherapy.
I believe that slight alternations of E2/E1 ratio happen because there’re mechanisms to do so. But as I’ve mentioned - it takes time of negative feedback loop to work (at best weeks). AI works almost immediately (matter of hours).
The problem is, people can’t dose their AI. That’s why I’ve created this topic: Estrogenic Side Effects No More - #9 by unreal24278
It’s really hard to crash your estrogens if you can manipulate your dosage of anastrozole by 0.05 mg, but it requires patience.