I don't use neither AI nor HCG.
Plain test prop without additional supplements.
Currently running 20mg/day test prop intramuscular.
With 10mg/day I get hardly any E2 conversion, I'm six pack lean.
If I had problems with high E2 I would look into Pregnenolone / Progesterone or use vitamin E.
Protocol is not perfect, but by far the best I have found.
Would like to inject less frequent, but I cannot make longer ester work.
For anybody starting out with Prop, I would recommend starting with 10mg/day and see how it goes.
You will actually know within 2-3 days if it works for you. That's how fast you achieve "stable" levels with prop (0.8 days half life).