I pretty muck lost all thyroid function about 10 years ago. My TSH was at 237 when I was first tested. Went on levoxyl and was all over the map on dosage. Needed lots of variations here and there on dosage, depending on how much I was working out (more needed when I was training a lot for Ironman triathlons).
My dose was pretty steady the last year or so @ 175mcg/day of levoxyl (generic snythroid). My symptoms were slowly returning even though my TSH was right around 1.2.
About two years ago I asked my GP to switch me to Armor as a test. I found I felt a lot better after about two weeks. I am on a 120mg dose (3 grains) and feeling pretty good.