It will make you sterile eventually, I think 6 months is the 'quote' but YMMV. It decreases 'male' libido and stops erections, it may change hair growth patterns to a more feminine distribution. Some people say it develops breasts but you get more effect on E when S has killed off T.
The effect of E may be quicker once T is killed, Oh and every endocrinologist has a different routine and I think they all work, it is just their preference.
I was on E alone and then went on S, same result.