T4 Only, Low TSH: Hi, I recently had blood tests... - Thyroid UK

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T4 Only, Low TSH

sukismum profile image
13 Replies

Hi, I recently had blood tests with my GP and now have a phone call appointment scheduled. My latest blood results 16/9/23 are as follows, with reference ranges.

FT4 = 18.7pmo/L (9 – 23) or 69.29% through the reference range

FT3 = 4.5pmo/L (2.4 – 6) or 58.33% through the reference range

TSH = < 0.01 mU/L (0.3 -4.2)

Vitamin D = 54.8 (50 – 150 )

No B12, Iron or Folate

I was diagnosed with an underactive thyroid 22 years ago (now age 64) since then have taken Thyroxine only, currently taking 125mg daily. Feel well.

I know my Dr is not going to be happy with the TSH result. When I went through this 18 months ago, I agreed to reduce to 125/100mg on alternate days, but could not cope with the cold winter weather so reverted back to 125mg each day.

Would it be fair to say that after so long on T4 my thyroid probably doesn’t even work anymore and my body relies solely on the supplementation of T4?

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13 Replies
Lalatoot profile image
Lalatoot

My TSH was under range on 100mcg levo with ft4 at 60% and ft3 at 17%. The only way to get my TSH back into range was to reduce my dose to 50mcg per day and that made me very ill as my ft4 dropped and my ft3 plummeted well under range.Hypos need ft4 to be over 50%through range to make up for the inefficient way their body processes the hormone.

You shouldn't lower your dose when you feel well and your thyroid hormones are well within range.

sukismum profile image
sukismum in reply toLalatoot

Gosh I can't believe you went through that hope you are in a better place now. Thank you for your comments and support.

jgelliss profile image
jgelliss in reply toLalatoot

👏👏👏👏

jgelliss profile image
jgelliss in reply tojgelliss

To me it never made sense to reduce the T4 portion to add T3. Unless the FT4 was very high and crowding the T3. Personally from my experiences lowering my T4's and raising my T3 made me feel very lethargic and over all not feeling optimal. I don't know if it has anything to do that I had TT and I no longer have thyroids that produce any thyroids?

TiggerMe profile image
TiggerMeAmbassador

You will have been taking a full replacement dose pretty much from the start after the initial build up, with a low TSH there is no signal being sent from your pituitary gland to your thyroid to produce any hormones.... your Vit D is low and likely that your ferritin, folate and B12 are too if you don't supplement.

You are still converting well and getting these thing up will help, refuse to reduce as you feel well and you are comfortably within fT3/4 range 🤗 TSH is irrelevant

sukismum profile image
sukismum in reply toTiggerMe

Hi Eeyore100, thank you for your comments and advice. I am planning to get a full panel of tests including B12, Folate, Ferritin and Vit D privately. Then look at better supplementing. This is something I am not good at. Thou.gh most importantly NOT agree to a reduction in T4

greygoose profile image
greygoose

Would it be fair to say that after so long on T4 my thyroid probably doesn’t even work anymore and my body relies solely on the supplementation of T4?

Thyroid hormone replacement (levo, etc.) doesn't 'top up' your hormone levels, as doctors seem to think, it shuts down your thyroid production by reducing/suppressing the TSH, and then completely replaces your natural thyroid hormone and increases levels - if you take enough of it!

So, no, your thyroid won't be working at all at the moment. But, that doesn't mean it's no-longer capable of working. If, for some reason, you stopped all exogenous thyroid hormone, your thyroid would go back to making what it was making before you started the levo.

So, yes, at the moment, you are entirely reliant on the exogenous T4 you are taking. And reducing the dose by too much - or stopping it completely - would make you very ill.

Your doctors should not be dosing by the TSH because once it gets below 1 it is totally unreliable, and a very poor indicator of thyroid status. So, just say no. You are not over-medicated because your Frees are still well within the range, whatever the TSH might say. And, your doctor is there to advise you, not to dictate to you. There is no law that says you have to do what he says.

sukismum profile image
sukismum in reply togreygoose

Hi Greygoose, many thanks for explaining how T4 works, I had no idea. I just thought the T4 balanced out with whatever your thyroid was able to provide. ( My TSH was 10.3 when I was first diagnosed). Also, the words of support for discussions with the GP. The telephone call is Thursday.

greygoose profile image
greygoose in reply tosukismum

You're welcome. :)

Starseed56 profile image
Starseed56

Wow you got the gp to do a vitamin D?! I asked for this two weeks ago explaining that I’m taking D supplements and am concerned not to over do it as that’s toxic. She looked at guidelines and read out to me, I ticked one box but apparently the gp can request and the lab decides based on other results. Seems it’s random across England. I get my results this week so will see then if they agreed to it I’m not holding my breath!

I’m three weeks into Erfa after 21 years on thyroxine, similar to you. Am feeling utterly awful and exhausted, headaches nearly every day, but am told this is normal when switching.

GPS never liked a low TSH I told them it’s when I felt best! I’ve more or less decided to switch to Thyroid S after reading and chatting with a knowledgable friend. I’m paying £77.50 for two months supply plus £20 prescription charge plus private doctor fee which is £87. I will do another medichecks in a few weeks time to see if my numbers have improved. I can’t sustain those costs for the rest of my life (am 67). I hate that even the private system can lock you in and it’s expensive, out of the reach of many. I won’t rant here about the broken system 🙄😉

Am finding this forum so useful and full of knowledge/experience. 💜

sukismum profile image
sukismum in reply toStarseed56

Hi Starseed56, hope you start to feel better soon with the new prescription. Thanks for your

SlowDragon profile image
SlowDragonAdministrator

vitamin D is too low

Essential to test B12, folate and ferritin

Refuse to reduce dose levothyroxine and get vitamin levels tested

Recommended that all thyroid blood tests early morning, ideally just before 9am, only drink water between waking and test and last dose levothyroxine 24 hours before test

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

List of private testing options and money off codes

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

bluehorizonbloodtests.co.uk...

Only do private testing early Monday or Tuesday morning.

Link about thyroid blood tests

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

Link about Hashimoto’s

thyroiduk.org/hypothyroid-b...

Symptoms of hypothyroidism

thyroiduk.org/wp-content/up...

Tips on how to do DIY finger prick test

healthunlocked.com/thyroidu...

Medichecks and BH also offer private blood draw at clinic near you, or private nurse to your own home…..for an extra fee

Just TSH, Ft4 and Ft3 test - £32

monitormyhealth.org.uk/thyr...

10% off code here

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

Monitor My Health also now offer thyroid and vitamin testing, plus cholesterol and HBA1C for £65

(Doesn’t include thyroid antibodies)

monitormyhealth.org.uk/full...

10% off code here

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

sukismum profile image
sukismum in reply toSlowDragon

Hi Slowdragon, thank you for all the information, link and advice, I will definitely be following up the with private tests especially Folate, B12 and Ferritin.

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