I was diagnosed in March. I was lucky, it was my first trip to the docs and I didn't suspect although I had major symptoms. My dose as increased gradually form 25ug, to now 100ug. Thing is in August my TSH was 0.8 and I felt fantastic (50ug dose at the time) Last month my TSH was over 10. I have been on 100ug for just over a week (75ug for 6 weeks before that) and I know not to expect settling just yet.
Looking back I suspect I was hypo for at least 18months before dx.
How long can I expect the ups and downs for?