No thyroxine before a blood test .

[TJc64]

Good Morning, I have s blood test this morning but took my thyroid medication last night at 10pm without thinking. Should I cancel the test . Would it give a false reading ? I have not eaten yet

Thank you

[greygoose]

What do you take? Levo? NDT? T3?

If it's levo, you would get a slightly false high FT4, but it won't affect your TSH. TSH is affected by the time of day and eating, not taking levo.

If it's NDT or T3, then the timing would be about right.

[TJc64 in reply to greygoose]

Thank you it was Levothyroxine.

[greygoose in reply to TJc64]

OK, so as I said, it won't make an awful lot of difference, and I don't suppose your doctor really looks at the FT4, anyway! lol

[108Optimist]

Its okay. 12h is long enough but remember this and make a note of it. Next time you have tests, do the same or of you do different, note that too. Keep a spreadsheet of all your results and include the 'washout' period eg time since you last dose.