Hi Dorit,
I'll add my experience with E levels as post op (3 years now), and I am 60. I first used patches 14 months (started at age 52), then IM (estradiol valerate) 6 years, and now this year I am back on patches, my levels were checked and I was at 72 pg / ml just last month. My Dr told me this is exactly where I should be given my age and HRT history. My levels are now in the expected "normal" range for post menopausal women. My 2nd puberty is over, I don't need anti androgen anymore (thank goodness), I am now in "maintenance mode" as an older post op. I don't need as much E in my blood as when I was first transitioning (subjective), and by the way I feel great !
Good luck to you
Cynthia -