With nothing other than HRT, my hair is growing back and has been for about 6 months. It is fine baby hair, but that will eventually fall out to be back filled by a thicker follicle. I asked my endo if I was hallucinating and she said "no, it is really happening'. She has seen it enough times and can remember how things looked back when I started. My partner has been snapping various pictures and has also told me the extent of the regrowth. Looking at the photos, there is definite progress.
I am not sure how much regrowth there will be, but is it not a pleasant surprise in terms of effect?