Here is an interesting article that might help.
Hypogonadism among men desiring fertility preservation presents a unique challenge to physicians. Over the past decade the number of younger men with hypogonadism has increased dramatically. These men are often treated with testosterone replacement ...
pmc.ncbi.nlm.nih.gov
“In healthy eugonadal men selected to undergo TRT it was shown that their intratesticular testosterone levels dropped by 94%. However, in those who received 250 IU SC every other day along with TRT their intratesticular testosterone levels only dropped 7%. Additionally, in men who received TRT and 500 IU of hCG every other day an increase in intratesticular testosterone by 26% was observed (
12). This proved that co-administering low dose hCG could maintain intratesticular testosterone in those undergoing TRT. It was later shown that not only is intratesticular testosterone increased with co-administration hCG but spermatogenesis is preserved as well at one year follow up”