Why would my FT4 change?

[DAB68]

Hi,

My thyroid has been ok for some years now, I have generally felt quite well. A recent GP blood test flagged up that my FT4 is at the bottom of the range. I am currently taking 120mg of NDT, I was on 240mg for many years but was told I must reduce my dosage as my TSH was 0.05. I reduced the dosage approx 2 years ago. Recently I have been feeling really tired and generally not well but put this down to my arthritis which always flares in the winter. I have been asked to come in and discuss my blood results with the GP, my cholesterol is also elevated but I do not want to take statins.

My FT4 was 10 and I am taking 120mg a day of NDT, they did not measure TSH. What is an "ideal" FT4 level whilst on medication.

Thanks

D

[Jaydee1507 Administrator]

NDT has a proportionately low amount of T4 compared to its T3 content so those on NDT often have a low in range FT4.

A low or suppressed TSH is usual when taking NDT as it contains T3 which almost always reduces TSH to next to nothing.

When are you taking your last dose of NDT before blood tests?

What time of day are your blood tests? Recommended timings are split dose of NDT before blood draw, taking last portion 8-12hrs before blood test.

Test at 9am or earlier for highest TSH.

Its more important to test FT4 AND FT3 on NDT.

What are your latest vitamin results - ferritin, folate, B12 & D3?

What supplements do you take?

Suggest you get some private blood tests run for a FULL thyroid panel - TSH, FT4 & FT3. Also vitamins if GP wont test.

See link for companies offering private blood tests & discount codes, some offer a blood draw service at an extra cost. thyroiduk.org/testing/priva...

There is also a new company offering walk in& mail order blood tests in London, Kent, Sussex & Surrey areas. Check to see if there is a blood test company near you. onedaytests.com/products/ul...

Only do private tests on a Monday or Tuesday to avoid postal delays.

[greygoose]

The ideal level for FT4 is where it makes you feel well. And nobody can know what that is but you.

I was on 240mg for many years but was told I must reduce my dosage as my TSH was 0.05. I reduced the dosage approx 2 years ago.

And how many blood tests have you had since then? What was your FT4 before. And do you have a range for it, please?

No, you didn't have to reduce your dose because your TSH was 0.05. They told you to because a low TSH scares the life out of them! Nothing to do with your health. But how did you feel on that dose? What were your FT4 and FT3 levels on that dose?

If your cholesterol is high then your FT3 is bound to be low! But I bet they never test that, which is total insanity. But doctors know so little about thyroid, it's not surprising.

I would advise you to keep on refusing statins, they can do far more harm than good. And your cholesterol is not high due to statin deficiency, it's due to incorrectly treated hypothyroidism.