Time of last T3 dose before blood test?

[k8sykes1977]

Hi all, quick question. If having an early morning, fasting blood test to include full thyroid panel, lipids etc. What time should the last dose of T3 be? Morning, Lunchtime or 3pm? TAI

[SlowDragon Administrator]

Recommended that all thyroid blood tests early morning, ideally just before 9am, only drink water between waking and test and last dose levothyroxine 24 hours before test

This gives highest TSH, lowest FT4 and most consistent results. (Patient to patient tip)

T3 ….day before test split T3 as 2 or 3 smaller doses spread through the day, with last dose approximately 8-12 hours before test

so last 1/3rd of daily dose around 8-9pm