couple of points I'll add to this... HCG can be usefull on a long cycle to maintain an rehabilitate your nut sack if you were on a previous long cycle prior and didn't use any ... that's my own personal finding.

While coming off when using aromatase inhibitors such as femara and arimidex you have to be carefull to wean off these... ie. taper off them as they are so strong they can actually eliminate all estrogen from your body, which effectively hyper-sensitizes your estrogen receptors.

Then once off the AI's any estrogen produced by your body even within normal amounts can cause things like gyno, suppression, mood swings etc.

Aromasin is a better choice IMO