FAQ from a thyroid website
should i take my thyroid on an empty stomach?
Although this is generally recommended, it is likely not 100% critical. For instance, in studies of older subjects in a nursing home, no significant changes in levels of TSH were detected if the thyroxine tablets were given on an empty stomach at midnight, versus after breakfast. The important lesson is to try and take your tablet at ~ the same time each day to minimize potential variability in absorption of the thyroid hormone