From what I have read on the subject. Anything over 500iu per injection will give you no significant improvement. With 250iu giving you enough to keep your gonads working. Half life is 4 days so once a week is a bit skimpy, twice a week or every other day makes far more sense. Also excessive testosterone produced in the testicles can convert to estrogen before anatrozole can do any good. If estrogen levels are an issue with you that is makes it a little harder to deal with.
Now I was assuming you are using HCG as part of a testosterone replacement therapy and not using it in some HCG only treatment. Or a temporary effort to see if your boys work. If that is the case I still think once a week is not good. But i always bow to those those who know more than I do.