Re: Difference in morning and afternoon testing
TSH in an unmedicated person will be highest in the hours between 9 at night and dawn. For testing purposes, if she can be waiting on the lab's doorstep when they open, she'll get a higher reading than she'll get for the rest of the day.
But in a medicated person, I'm not sure that will work to achieve a high TSH. The med messes with the pituitary, and I'm not sure it will very quickly adjust and spew out a lot of TSH just because one day's med is skipped.
And I don't know what happens to FT3/4, either. I don't think they adjust within mere hours, but I'm not sure.