How long to wait to test if over supplementing ... - Thyroid UK

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How long to wait to test if over supplementing thyroxine

Bellsonit profile image
12 Replies

Hi this is kind of hypothetical- If you were to take 25mg levothyroxine over your gp prescription and wanted a new blood test without the extra showing how long should you wait from stopping the extra to taking the test?

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Bellsonit profile image
Bellsonit
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12 Replies
Lalatoot profile image
Lalatoot

You really would want to see what difference the extra 25mcg had made to your blood results. So you could see the levels you wished to be at if it made you feel better.

Bellsonit profile image
Bellsonit in reply to Lalatoot

Thank you - I agree it would be good to see the differences between both. It’s been so long since I tested. Last was October 2020 it should be yearly but with covid and stock shortages it’s not classed as urgent. During this time I started to over supplement by 25mg due to many symptoms so I think I need to reset back to what results are supposed to be on correct dose then test privately after a period of the increased doses. Life has been a bit chaotic - work exceptionally busy and I face into nhs so it’s manic and I’ve not focussed on myself.In the last few months I’ve been feeling very low, my hair is thinner, I’m constantly tired and I’ve gained substantial weight (2.5 st in 2 years) and a big calorie deficit still it takes me forever to drop weight.

Could be thyroid could be something else which is why I think if I can put a line in the sand and properly keep an eye on results I can help myself better.

My TSH levels don’t really change hardly at all. They are always under range even with a decrease in meds they are under range.

I started monitoring after about 18 years of thyroid issues. Diagnosed at 18 due to goitre and it was deemed as hashimotos - I’ve only ever been given thyroxine .

For years I hovered between 150 mg and 175mg levo then gp started reducing due to tsh levels.

Oct 16 - 150mg

Free T3 6.7 and

TSH 0.02 at 11.45am

Jan 17 reduced to 125mg

free T3 - 3.6 (range 3.1-6.8) and

TSH 0.17 (range 0.3 - 5.0) at 8.45am

March 20 - 150mg levo

0.02 (range 0.3-5)

Serum free triiodothyronine 4.9 range 3.1-6.8

Oct 2020 - 150mg

At 8.40am

Tsh - 0.02 (range 0.3-5)

Serum free triiodothyronine 5.1 range 3.1-6.8

Ferratin - 60 (range 15-350)

Thriva

Nov 20 - 150mg

Tsh - 0.01 (range 0.27-4.20

T4 total - 114 (range 66-181)

Free t4 - 21.2 (range 12-22)

Free t3 - 4.65 (range 3.1-6.8)

Tpa- 29 (range <34)

Tgab - 1391 (range <115)

shaws profile image
shawsAdministrator in reply to Bellsonit

If you have gained weight it could be due to you not being on a sufficient dose of thyroid hormones.

stopthethyroidmadness.com/h...

tattybogle profile image
tattybogle

hypothetically .... Assuming it's a low TSH you want to increase ....

Leaving a longer gap will reduce the fT4 result ...but will do nothing about the TSH result ... because :

fT4 result is like 'a window onto today' ....it shows what is still left in your blood today from the Levo you took over the previous couple of days (+ smaller amount that is left over from previous week ... levo has 7 day ' half life' )

TSH is more like 'a window onto the recent past' ...... it shows what Level of Levo you were taking consistently over the last few weeks .

TSH can take a long time (weeks) to move in response to subtle/small dose reductions So you won't get TSH to move much (if at all ) by just reducing your dose back to prescribed dose for even a week before a test.

Getting TSH to move can only be done by changing dose 'a little bit , for lots of weeks' . or changing dose 'a lot , for less weeks'

There isn't a way to do it without making yourself feel unwell for a period of time.... That's one of the reasons they like using TSH so much .. it allows them to see what you 'were doing' , not just 'what you did for a day or two when you knew you had a test coming up '

In a patient on Levo , if they see an unexpectedly high TSH , but fT4 is as expected ... they will ask if you have been "forgetting to take your levo regularly ",( but remembered to take it for a couple of days before the test).

fuchsia-pink profile image
fuchsia-pink

It takes a short time for frees to drop and a long time for TSH to increase (if ever). That's why we say a gap of 24 hours is best to give a proper representative level of hormone. If you have your bloods taken sooner you get a "false high" - sometime quite alot higher - and if you leave a longer gap you get a "false low". If you were to leave a 3 day gap, your results would prob be on the floor. Even 2 days would put them much lower than with the "standard" 24 hour gap.

If you were to do that, you should also have a private test done under proper conditions so you know what your real results are ...

Bellsonit profile image
Bellsonit

Thank you - I agree it would be good to see the differences between both. It’s been so long since I tested. Last was October 2020 it should be yearly but with covid and stock shortages it’s not classed as urgent. During this time I started to over supplement by 25mg due to many symptoms so I think I need to reset back to what results are supposed to be on correct dose then test privately after a period of the increased doses. Life has been a bit chaotic - work exceptionally busy and I face into nhs so it’s manic and I’ve not focussed on myself.In the last few months I’ve been feeling very low, my hair is thinner, I’m constantly tired and I’ve gained substantial weight (2.5 st in 2 years) and a big calorie deficit still it takes me forever to drop weight.

Could be thyroid could be something else which is why I think if I can put a line in the sand and properly keep an eye on results I can help myself better.

My TSH levels don’t really change hardly at all. They are always under range even with a decrease in meds they are under range.

I started monitoring after about 18 years of thyroid issues. Diagnosed at 18 due to goitre and it was deemed as hashimotos - I’ve only ever been given thyroxine .

For years I hovered between 150 mg and 175mg levo then gp started reducing due to tsh levels.

Oct 16 - 150mg

Free T3 6.7 and

TSH 0.02 at 11.45am

Jan 17 reduced to 125mg

free T3 - 3.6 (range 3.1-6.8) and

TSH 0.17 (range 0.3 - 5.0) at 8.45am

March 20 - 150mg levo

0.02 (range 0.3-5)

Serum free triiodothyronine 4.9 range 3.1-6.8

Oct 2020 - 150mg

At 8.40am

Tsh - 0.02 (range 0.3-5)

Serum free triiodothyronine 5.1 range 3.1-6.8

Ferratin - 60 (range 15-350)

Thriva

Nov 20 - 150mg

Tsh - 0.01 (range 0.27-4.20

T4 total - 114 (range 66-181)

Free t4 - 21.2 (range 12-22)

Free t3 - 4.65 (range 3.1-6.8)

Tpa- 29 (range <34)

Tgab - 1391 (range <115)

SlowDragon profile image
SlowDragonAdministrator

Essential to test vitamin D, folate, ferritin and B12 too

What vitamin supplements are you currently taking

When were vitamin levels last tested

Suggest you get FULL Thyroid and vitamin testing done yourself privately now on the dose you’re currently on

thyroid blood tests should ideally be done as early as possible in morning and before eating or drinking anything other than water and last dose levothyroxine 24 hours before test

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

Private tests are available as NHS currently rarely tests Ft3 or all relevant vitamins

List of private testing options

thyroiduk.org/getting-a-dia...

Medichecks Thyroid plus antibodies and vitamins

medichecks.com/products/adv...

Blue Horizon Thyroid Premium Gold includes antibodies, cortisol and vitamins by DIY fingerprick test

bluehorizonbloodtests.co.uk...

If you can get GP to test vitamins then cheapest option for just TSH, FT4 and FT3

£29 (via NHS private service ) and 10% off down to £26.10 if go on thyroid uk for code

thyroiduk.org/getting-a-dia...

monitormyhealth.org.uk/

Bellsonit profile image
Bellsonit in reply to SlowDragon

Hi thanks again. I just have one more question sorry. Do you think it’s worth getting crp, cortisol and magnesium done?

SlowDragon profile image
SlowDragonAdministrator in reply to Bellsonit

Cortisol may be useful

Especially if you feel worse in mornings and less unwell afternoon/evening…..can suggest cortisol issues

Remember to stop taking any supplements that contain biotin a week before all blood tests..as biotin can falsely affect test results….eg vitamin B complex

Bellsonit profile image
Bellsonit in reply to SlowDragon

Asking as just comparing the different tests

Bellsonit profile image
Bellsonit

Thanks my full vits and minerals were tested nov 20 so a lot are due. So will definitely do a test privately . To start with I was taking selenium and vit b biovailable that was recommended here but that’s taken by the wayside and I need to sort myself out. Life has just got in the way and I’ve been feeling progressively worse. I would say my mh probably the worse of the lot of my symptoms

Bellsonit profile image
Bellsonit

Thanks for all of your advice. I've currently got the GP testing my thyroid and also a number of other things. I'll await their results and will also do a private tests as GP isn't doing full vitamins.He has ordered TSH, T3, T4, Liver Function, Kidney Function, Calcuim and Phosphate (had a screening recently and the phosphate was over range), Full Blood Count (Mean Cell Volume high during screening, Mean Cell Haemaglobin Concentration low during screening), Ferritin, Ttg and Folate.

So there are some I need to get - thyroid antibodies (my thriva TGAB were 1391 and TPA 29 in my last private test), Vit D (generally low end during tests) and Vit B12.

Do you think its worth me trying to get an endocrine referral? Every time I show GP my test results they focus on TSH which typically ranges from 0.01-0.02. My last 4 bloods for Free T3 are averaging 4.8 so around 48% through range but lately i've had awful symptoms.

Depression, Considerable Weight Gain, Slow Heart Rate (typically resting around 50), Tiredness, Foggy and regularly can't get my words out

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