Good question.
It's not so much about "desensitization" (if that even exists) as it is the concern for increase in unwanted E2
When a man utilizes high in levels of HCG, say in the range of 350 iu daily, it can/may increase E2...but more importantly, it can/may increase intratestesticular E2---which an AI is largely ineffective in controlling.
I love Dr. Crisler's approach to the use of HCG: no more then 350 iu on any one dosage and no more then two of those dosages a week with the exception of transdermal users where he like 100 iu daily of HCG.
Personally, I like even smaller doses more frequently if you inject IM.
I do HCG 250 iu Monday, Wednesday and Friday and all is good including E2
