I can't comment on Zoladex. But I was on Tamoxifen not for Breast Cancer, but being at a high risk.
My side effects for the first few months was........... irregular periods, a crawling feeling on your head, hot flashes, night sweats, joint pain. After a few months the side effects had pretty much gone away, except for the night sweats, but after all the side effects, I still feel like the Tamoxifen was worth taking. I hope this helps.
(I started Tamoxifen at 35, and finished at age 39)
Thanks very much for your comments, really helpful