T3 24 hours before Test

[Sami-M]

My last tests I took my T4 & T3 , 24 hours before test, by mistake. Madness! After the test I added an additional 6.25mcg T3. Only just realised as my insulin resistance has kicked in massively.

Tests- Otherwise, fasting yes, no biotin.

So I took both 24 hours before test; T4 131.25 mcg & T3 6.25 mcg

Is it possible to work backwards and guesstimate what my FT3 would have been if I had had the last T3 dosage 12 hours before.

RESULTS : 22 December 2023

TSH: 0.005 mU/l (0.35 - 5.5) -6.70%

FT4: 20.8 pmol/l (11.9 - 21.6) 91.75%

FT3: 5.18 pmol/l (3.1 - 6.8) 56.22%

[Lalatoot]

Sami. Do you dose your t3 once per day? If yes then the 24 hour gap measures the lowest level your ft3 gets to on a typical day. In other words you always have 56%of t3 left in your system.

[Sami-M in reply to Lalatoot]

Thank you Lalatoot, yes I normally take T3 & T4 in the morning only. Would there be anyway to guess the FT3 that would have been indicative of the FT3 I would have expected if I had split the 6.25mcg, and taken last dose 12 hours before testing ?

[Lalatoot in reply to Sami-M]

I don't agree with splitting your dose the day before a blood test. For me because you altered that dosing pattern then your blood hormone levels will not be typical of what your body normally has to work on.

[Sami-M in reply to Lalatoot]

Thank you lalaloot, I never knew. I thought it was the only way, last dose Levo 24 hours & T3 12 hours prior to testing. So I’m fine, then and as SlowDragon suggests, need a little drop in the Levo & the additional 6.25mcg T3.

[Lalatoot in reply to Sami-M]

Just change 1 thing at a time. That way you know what is causing any benefits or symptoms.

[SlowDragon Administrator]

You might need slightly less Levothyroxine and a bit more T3

perhaps reduce Levothyroxine to 125mcg 3 days per week and 131.25mcg 4 days

Retest in 6-8 weeks

[Sami-M in reply to SlowDragon]

I increased the T3 to 12.5mcg but kept Levo at 131.25mcg. My insulin shot up. Yes, I will drop a little Levo and maintain the additional T3. Thank you SlowDragon