Re: Time medication remains in body...
Well... It doesn't exactly work that way. Even though your last dose may be half gone, it isn't as if it was working for you as soon as you took it. Your body operates on the stored T4 that converts to T3. The dose you take per day goes into storage for later use.
In simplest terms, it takes time... several weeks, probably... for the blood level of T4 to drop once you stop taking med. If I remember right, your FT3 was slightly above range. It would take maybe a week or more for it to drop into mid-range.
Good luck with the new doc!