Thyroid blood tests and dose timings before

[mistygrey]

Hi, I have thyroid bloods tomorrow 830am, I usually miss my 7am t4 dose before blood tests but I am also on T3 at 3pm every day. Do I take a dose of T3 anytime before my bloods or just leave both T3/T4 until after blood draw tomorrow? Some are advising me to take my T3 dose around 12 hours before my blood draw? I usually take T3 at 3pm every day, so that would mean instead it would be 830pm tonight? Which is best? Thanks ☺️

[SeasideSusie Remembering]

mistygrey

When taking thyroid hormone replacement, last dose of Levo should be 24 hours before blood draw, if taking NDT or T3 then last dose should be 8-12 hours before blood draw. Adjust timing the day before if necessary. This avoids measuring hormone levels at their peak after ingestion of hormone replacement. Take your thyroid meds after the blood draw. Taking your dose too close to the blood draw will give false high results, leaving any longer gap will give false low results.

It would be best to delay this afternoon's T3 dose until some time between 8.30pm and midnight.