HCG is very valuable in HRT. One protocol is fairly popular, and involves test injection 1x/week with low dose HCG on days 5, 6. So if you were pinning test on Saturday, you would pin HCG on Thursday and Friday of the next week.
The goal is two-fold. (1) it prevents testicular atrophy. not a medical problem, but for some it's an aesthetic thing. (2) it evens out your test levels. As the test levels in your blood are fading at the end of the week, the HCG gives your levels a slight boost, so that you feel more even when pinning 1x/week. I suppose if you cut your dose into two equal amounts and pin 2x/week, you would have less need of it.
Another thing that I think you should consider is whether the HCG will help you recover what little natural production you had before HRT in the event you ever need to get off the HRT. The HCG looks like LH to the body and signals to the testes to keep producing "naturally." If you ever need to come off the test, at least your testes have been working over the years, and this may aid in getting whatever natural production you still have on line.
check out
www.allthingsmale.com. In the papers section, it discusses an HCG protocol.