On T3 should you have blood tests for t3 - Thyroid UK

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On T3 should you have blood tests for t3

44 Replies

Hi I have just come back from my Endocrine app he put me on 10mcg in June with 100 Levo I was already on for over a year just t4 only.. but 3 weeks ago I cut t4 down to 75mcg as I was over range on t3 but my Endo now says its not that important to test t3 as t3 fluctuates thro out the day I thought being on t3 we should have our t3 bloods tested as well as the tsh t4? he is saying he is happy to carry on providing my t3 but so long as I'm aware the affect my suppressed tsh has on my heart n bones my tsh had been suppressed for a year on t4 only! being in range twice in all that time. I've had osteoporosis since 2016 and my heart scans shows heart structure is good but mild to moderate mitral valve probs so having yearly check ups so why now is he going on at me about this t3 n supressed tsh they didn't test t3 this time only tsh and t4

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44 Replies
fuchsia-pink profile image
fuchsia-pink

Yes, you should test free T3, as you don't want this to be over-range for a long period of time [it is this, not having a suppressed TSH, which is something that just happens, that is potentially dangerous].

And yes, T3 does fluctuate a lot during the day - it has a very short half life. For this reason it's important NOT to test it just after you've taken your lio (hen it would show your highest possible reason) and why this forum recommends a gap of 8 - 12 hours (applied consistently)

If anything, it's testing TSH which is a waste of time, as this is inevitably suppressed when taking lio x

in reply to fuchsia-pink

Thank You!

serenfach profile image
serenfach in reply to fuchsia-pink

TSH has a half-life of about an hour and can vary as much as 50% over a day. For clinical interpretation of laboratory results it is important to acknowledge that TSH is released in a pulsatile manner resulting in both circadian and ultradian rhythms of its serum concentrations.

Hoermann R, Midgley JE, Larisch R, Dietrich JW (20 November 2015). "Homeostatic Control of the Thyroid-Pituitary Axis: Perspectives for Diagnosis and Treatment"

T3 has a half life of around 60 hours and is considered stable in a person taking T3.

Maybe send the above to your Endo, he is out of date.

SeasideSusie profile image
SeasideSusieRemembering

Gsd2011

It's the most important test, especially when taking T3. How will your endo know whether your are taking too much or too little T3, how can he adjust your dose if he doesn't test FT3? Methinks he is yet another endo who is prescribing T3 but hasn't got a clue about it 🙄

in reply to SeasideSusie

Well it's 6months till I see him again any questions I ask he either dismisses it or goes on about the weather or something really annoying strange little man

shaws profile image
shawsAdministrator in reply to

He may not give you an answer to your question as he may not be knowledgeable enough to do so,

in reply to shaws

Apart from getting t3 prescribed been of no help I thought in beginning I would but 6 years on no advice nothing I just hear about numbers and suppressed tsh never actually asks how I'm feeling if I can get in with how I'm feeling before he cuts in and always dismisses things might as well stayed with my gp

greygoose profile image
greygoose

T3 doesn't fluctuate through the day nearly as much as TSH does. And yet the majority of doctors are quite happy to just test the TSH and adjust the dose accordingly, no matter what time the blood draw. They only take notice of these things when it suits them!

in reply to greygoose

Since I cut down my t4 to 75mcg from a 100 I won't know what my results are till I test myself or try get my gp to test them all I know my t4 has gone down since I was over range t3 ill give it another 3 weeks and see

greygoose profile image
greygoose in reply to

Well, it would go down if you reduced the dose and started T3. Taking T3 would make it drop anyway, even if you didn't reduce the levo. What was your FT4 before you reduced it?

If a doctor refuses to listen to me, I just keep repeating the same thing over and over until they are forced to take notice, even if it's only to shut me up! I will not be ignored.

in reply to greygoose

I would love yo be in the room with you n my Endo ha ha

greygoose profile image
greygoose in reply to

Bet he wouldn't! lol

in reply to greygoose

Sorry My Ft4 was 15.1 range 7.9- 16 in Sept so I cut it down to 75mcg with 10mcg so it's early only 4 weeks ago but my Endo did some 12th Oct my t4 gone down to 12 no t3

greygoose profile image
greygoose in reply to

Yes, well, it probably wasn't necessary to reduce your levo at all, because just taking T3 will reduce the level so it wouldn't have been too high.

in reply to greygoose

Shall I stick to 75mcg with my 10mcg? Or go back to the 100mcg Endo said stay at 75 its 6 months till I see him again

greygoose profile image
greygoose in reply to

Would you have enough to go back to 100 mcg? You don't want to run out before your next prescription.

in reply to greygoose

Yes I still have enough I'm sure I can still get 100mcg off my gp my Endo only supplying the t3 I thought it best to cut down maybe I should have just cut down for short time I'm still learning

greygoose profile image
greygoose in reply to

Cutting down for a short time wouldn't have helped anything. Endos think there is some god-given law that says you have to reduce the levo when adding T3, regardless of the FT4 level. But, there's no real reason why unless the FT4 was over-range and causing symptoms. Reducing it just for the sake of reducing it just rediculous. And, if you ask them, they have no idea why they're reducing it. That's just what they do. lol

in reply to greygoose

Thank you greygoose I'll say goodnight n pop my 100mcg Levo 😴 that's another thing he said why do you take levo at night start to take both t3 t4 in mornings

helvella profile image
helvellaAdministratorThyroid UK in reply to

Surely he gave a solid evidence-based reason for this suggestion/command?

greygoose profile image
greygoose in reply to helvella

I should imagine his only reason was that that was what he learnt in med school - like automatically reducing levo when adding T3!

in reply to helvella

No helvella he didn't he is very hard to challenge as I said he is very dismissive when you ask questions

waveylines profile image
waveylines in reply to

A sure sign ge doesn't know when he dismisses your questions like rhat!

in reply to waveylines

Everytime I come out of Endo visit I go in feeling ill get answers n come out feeling not listened to and lower in myself I was looking at your profile mine started off too nany years ago with small patches of vitiligo 1988... roll on 2014 all other auto immune things started but didn't get diagnosed till another year 2015.. 6 years on I've gone from fitness person to a shadow of myself my hairloss now is horrid not sure who to go and see about it just to know what sort of hairloss I have

waveylines profile image
waveylines in reply to

Am sorry to hear this. Am afraid many endos are not well trained in the management of hypothyroidism. Many specialise in diabetes and not thyroid conditions so know extremely little. So often patients are under treated or not treated. I found I had to become the knowledgeable one with reading books (list on thyroid uk) & great advice from knowledgeable people on here. Its a sad truth am afraid. Knowledgw is power! Also worth doing your own panel of thyroid bloods....finger prick test sent in post. Sources on thyroid uk.

in reply to helvella

🤣🤣

greygoose profile image
greygoose in reply to

You're welcome. :)

in reply to greygoose

Hi greygoose being not myself this morning a very bad sleep n sweating badly I've forgot my t3 dose 7am any idea's what best I do?

Stourie profile image
Stourie in reply to

Hi just take it now. I just take mine when I get up which could be 6 o’clock or 8. It doesn’t effect me at all. Jo xx

greygoose profile image
greygoose in reply to

Take it now. I agree with Stourie . I take mine when I just happen to get up. It was 11.15 this morning! lol

shaws profile image
shawsAdministrator in reply to

I would always take 'how I feel' on a particular dose rather than have a blood test.

Before I was diagnosed I had never heard of hypothyroidism but neither did any of the doctors I saw and I had never heard of hypo but neither did any of the specialists/doctors I consulted. Even my GP phoned to tell me my tests were fine and I had nothing wrong one hour after I had a blood test.

I cried as I felt so awful. I then went straight to the hospital with a blood test form I had requested when away from home. As it was the second blood test that day the A&E phoned surgery to ask why I had two blood tests! It's a good job I did as my TSH was 100 despite the GP phoning earlier after first result to tell me that my blood tests were fine and I had no problems.

in reply to shaws

It's awful no confidence I have anymore my only way I've got by is on here t3 n t4 not as simple as t4 only

in reply to greygoose

Your so right my Endo keeps chopping n changing his mind never listens to my questions I try to ask he certainly doesn't like you knowing too much he turns a deaf ear n dismisses me well he won't be upping my t3 anymore and lowering t4

SlowDragon profile image
SlowDragonAdministrator

You should retest full thyroid and vitamin testing a minimum of 8-10 weeks after any dose reduction in levothyroxine or T3

Waiting 12-16 weeks might be better

What vitamin supplements are you currently taking

When were vitamin D, folate, ferritin and B12 last tested

For full Thyroid evaluation you need TSH, FT4 and FT3 tested.

Very important to test vitamin D, folate, ferritin and B12

Low vitamin levels are extremely common, especially with autoimmune thyroid disease (Hashimoto’s or Ord’s thyroiditis)

Low vitamin levels common as we get older too

Recommended on here that all 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

On day before blood test, split T3 into 3 smaller doses, at roughly equal 8 hour intervals, taking last 1/3rd of daily dose approx 8-12 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...

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/

NHS easy postal kit vitamin D test £29 via

vitamindtest.org.uk

Are you on strictly gluten free diet?

Mitral valve is common with Hashimoto’s

webmd.com/heart/news/199911...

in reply to SlowDragon

Hi Slowdragon, all my vitimins are very good atm b12 ,vit d ,folate, ferritin I take vit d3 k2 folate iron tablets ,selenuim, b complex cut out gluten anything else missing?

SlowDragon profile image
SlowDragonAdministrator in reply to

If thyroid levels drop after 12-16 weeks …..recommend you check vitamins

SlowDragon profile image
SlowDragonAdministrator in reply to

You probably don’t need folate and vitamin B complex

Only one or the other

Never take iron supplements without doing full iron panel test regularly. 3-4 times year

medichecks.com/products/iro...

When were vitamin levels last tested

in reply to SlowDragon

All vitimans checked recently b12,folate, vit d, ferritin not had iron checked since April! in June I started taking ferrous sulphate 2 to 3 a day ferritin has gone from 77 to 160 range 15-300 need to get iron panel done again

Wired123 profile image
Wired123

Has there been a study showing the daily rhythms of TSH, T3 and T4 for people on replacement of T4 and/or T3?

Would be interesting to see and to stick under a doctor’s nose.

helvella profile image
helvellaAdministratorThyroid UK in reply to Wired123

It would be good to see such a study.

thyr01d profile image
thyr01d

Hi, curiously my endo has also just adopted the same attitude, I wonder if there's some new perhaps more compelling evidence about T3 and the problem with bones and heart. He's also told me not to have my morning T3 on the day of testing and to fast overnight which is new. Anything to please!!!

JaneChapple profile image
JaneChapple

Hello GSD2011

That man doesnt have a clue does he, but rhen most enods sont or drs for that matter?!

Out of interest which area are you in, I ask because Devon will only allow a maximum of 10mcg for everyone regardless of their clinical need. Also ranges vary throughout the country which of course will make a difference to where the result ends up. T3 is the only test needed when you take liothyronine, the rest are irrelevent bit of course the main point is how you feel on each dose change. Id keep a note of symptoms and then you can compare which dose is good for you. T3 needs to be in top half of range for most patients to feel well.

Have you got any recent results together with their ranges, especially the T3?

Janexxx😥😣😎❤

in reply to JaneChapple

Hi Jane, I'm in the Essex area Sept my gp did full tsh t4 t3 so early days since I cut my levo down to 75mcg with my 10mcg T3 I was over range t3 in September

Sept 20th
in reply to JaneChapple

My Endo did tsh t4 last week no t3 all I know is t4 now 12. The same ranges as Sept one above my tsh as usual supressed I'll have to wait few more weeks to test t3 only just changed doses 4 weeks ago t4 75mcg t3 10mcg I think maybe I should have stayed on 100mcg Levo but im new to this combo

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