T3 and T4: Hi all Happy New year! I have... - Thyroid UK

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T3 and T4

Topes009 profile image
6 Replies

Hi all

Happy New year!

I have recently started taking t3 alongside t4, has been t4 only for 30 years. I am currently taking 50 t4 and 2 x T3 5mcg daily. I reduced slowly following advice on here and must admit for a few days I felt good on 75 t4 and 1x t3 but continued to reduce t4 as advised by endo. I am slowing down now, very cold, very tired and bloating. I feel I need either more t4 or more t3. I also have rosacea which is getting steadily worse with this reduced dose.

I am 4 weeks into this T4/T3 dose and realise that is early days but I really don’t want to get any worse. My Endo is a tsh puritan and when challenged about ft3 levels he said they don’t count as they don’t show what is in the tissues. Very frustrating. He is very blase about it all.

I am thinking I should get bloods done and then schedule a call with him to raise t4 but thought people on here may have a good idea of what course to take and also what to say if my tsh is stil low, which it will be as it always has been and I believe t3 suppresses it anyway. I had a thyroidectomy and have hashimotos, although I was over active rather than under.

Any words of wisdom would be greatly appreciated. Apologies if this is all a bit scrambled.

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DippyDame profile image
DippyDame

when challenged about ft3 levels he said they don’t count as they don’t show what is in the tissues.

OK... I'll try to explain briefly!

The labs show the FT3 level in the serum and for most people ( except a very low cohort who have a form of thyroid hormone resistance....like me) it can be assumed that if FT3 is adequate then cellular T3 is also adequate.

FT3 level is an essential diagnostic reading....it is the most important result followed by FT4

For good health every cell in the body needs to be flooded with T3 by way of a constant and adequate supply....but our only way of assessing this is by an FT3 test.

Does he know that there are no tests to measure cellular T3....and that different cells require different levels of T3!

And does he also know that ultimately the cellular level of T3 is vital....T3 only becomes active once it reaches the nuclei of the cells and attaches to the T3 receptors...it can then get to work in various parts of the body as is required

T3 in the serum is not active until it is transported to cellular level

So in theory he is partly right FT3 doesn't show what is in the cells.... but he clearly doesn't understand the implications of this.

Low FT3 = poor health

Depending on the status of your T4 to T3 conversion reducing your T4 may also have reduced your T3. So dropping your T4 dose has likely dropped your T3 level

It's not always necessary to reduce T4 when T3 is added

Does he also know that T3 lowers both FT4 and TSH.

You need to increase/ adjust your T4 /T3 back to where you felt well

TSH is not a reliable marker after medication is initiated....it was devised as a diagnostic test for hypothyroidism ( high hormone levels) Nothing more! But it has been tweaked and used as a lazy way to monitor medication doses with the result that many patients remain unwell due to poor management

thyroidpatients.ca/2021/07/...

They are treating numbers not the person...and forgetting that we are all different!

Your symptoms indicate that you are now undermedicated!

Have you optimised vit D, vit B12, folate and ferritin to support the treatment

He ( endo) is very blase about it all....that's because he is covering up his ignorance! He is flying by the seat of his pants!

Yes....have a full thyroid test to include TSH, FT4, FT3, vitamin D, vitamin B12, folate and ferritin

As you probably know many of us test privately to achieve all those lab results

thyroiduk.org/testing/priva...

Nothing scrambled about your post....but can you now please add any results you do have so that we get a better idea of your treatment status.

Rant over!!

We're all here to help....just ask!

Topes009 profile image
Topes009 in reply to DippyDame

Thank you for your reply.

I was aware of how important FT 3 levels are and was trying to articulate that to the endo when he came out with that reply! (As an aside, GPs no longer routinely test ft3 which is just ridiculous)

Have booked a blood test but unable to get one until the week after next, should I increase my t4 back to 75 and take the 2x 5mcg of T3? I was taking 75 T4 with 1x T3 during the phase I was reducing the T4 and adding in T3. Should I do this prior to the blood test or contact the endo and tell him I need more T4? I don’t want to go over medicated again but equally don’t want to continue as I am. Apart from the other symptoms the rosacea worsening seems connected to this somehow, either the reduced dose or the T3 itself.

Prior to changing I was taking 100mcg T4.

October 23

Tsh 0.05 (0.38 - 5.33)

Ft3 4.5 (3.8 - 6.0)

FT4 12.7 (7.9 - 14.4)

These are the latest results at that dose.

I am taking iron as ferritin low also b12, minerals, omega oils, vit d and k.

Thanks for your help

Topes009 profile image
Topes009 in reply to Topes009

Also…the dosage of 100 T4 was a reduced dose from 150. I had been on that dose for 20 years with no issues but all went haywire last year. I believe it was connected to HRT. I have stopped HRT.

DippyDame profile image
DippyDame in reply to Topes009

We need to be on a steady dose of hormone for at least 6 weeks before testing so that it settles in the system.

If you alter your dose now and test in only a couple of weeks the results will not be reliable.

So you will either need to alter dose now and wait 6 weeks to test or, continue on current dose for a total of 6 weeks/ until the booked test, then alter dose according to test results.

I wish there was a quick fix but sadly there isn't....it's a long slow journey

The last time a GP tested my FT3 was in 2001!!

Post your new results, including ranges, and the dose you have been taking, so that we can see what is going on

Good luck

Topes009 profile image
Topes009 in reply to DippyDame

Thanks for that

Emailed the endo re upping to 75. He’s fine with this so will start that and delay the blood test for 6 weeks. Thank goodness he’s ok with it.

DippyDame profile image
DippyDame in reply to Topes009

Good decision!

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