Scoopy, I've never been on that med, but since it is closely related to amitriptyline I'd bet it will take a couple of weeks. My doc started my dose at 25mg and I was to double that after a week. Couldn't do the 50. Too sleepy from it. So I am still at 25, but take a different daytime med. Just out of curiosity, did your doc say why nortriptyline and not amitriptyline?