We discussed this recently in another thread. The original poster may wish to use the search function to find it. In that thread, I posted links to these two papers. I believe both are available free (open access):
https://www.ncbi.nlm.nih.gov/pubmed/15713727
https://www.ncbi.nlm.nih.gov/pubmed/...t%3A+an+update
Bottom line is that optimum dosing of HCG for fertility appears to be in the 1000 IU per week range. This level will bring Inter testicular Testosterone levels (ITT) up to near "normal". ITT is important for sperm cell maturation. I've seen numerous anecdotal accounts, like the one posed EZE in this thread, that lower dosing will also work. Some have reported success at levels as low as 500 IU per week.