Ya, that was me.
On HRT, HCG prevents/reverses testicular shrinkage, and increases adrenal function through the conversion of cholesterol to pregnenolone via the P450 SCC liver enzyme.
HCG increases endogenous testosterone production resulting in a larger overall total testosterone level.
HCG also increases well-being through a differant mechanism than increased testosterone. It may be from increased adrenal function, or it's LH agonist properties, or some other unknown function.
Aromasin works similarly to Arimidex and Letrozole, by decreasing estradiol levels which then increase LH.
When on TRT taking an AI or SERM will not prevent shutdown due to supraphysiological levels of T. If you go off TRT an AI or SERM will increase T due to T levels being low at this time.
Both testosterone and estrogen increase the feedback loop that lowers endogenous production of T.
The reason I chose Aromasin wasn't for any special reason. It seemed to have a more favourable side effect profile (lipids, cholesterol, libido), but it ended up not being strong enough, therefore I am going to switch to Arimidex to see if it will do a better job lowering my E2 levels.