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Latest results? Advice pls and I converting T4 into T3?

Here are my latest results from 2.11.16 I had my Levothyroxine increased from 75/100 which I was only on 10 days due to a severe flare so my Endo increased it to 100 every day. I have a follow up blood test Wednesday with an appointment to see my Endo on the 29th. He said if I've not improved (which I haven't I think I feel worse but darent say) he'd write to my GP to request a T3 trial. My FT4 is high does this mean I'm not converting? My Endo also said I have evolving thyroiditis and this is reflected in my repeated blood tests as my TSH keeps increasing so in turn does my levothyroxine. This isn't stopping me from having repeated chronic thyroiditis flares and ongoing hypo & hyper symptoms.

TSH 2.4 (0.27-4.2)

FT4 25.6 (12.0-22.0)

FT3 4.2 (3.1-6.8)

Previous to this my TSH was 0.83 and FT4 15.9 sorry no FT3 although looking back my FT4 has always been high even back in May it was 25.3 when I was on 100mcg and it was lowered to 75mcg and my FT3 4.4.

Thank you

16 Replies

Well, you are converting some, but not very well. You FT4 is much too high, but your FT3 is just under mid-range. Your TSH is too high, too. When on thyroid hormone replacement, it should be 1.0 or under.

Keep increasing the T4 is not the answer, because then you have a load of unconverted T4 running around, which could convert to rT3. So, what your doctor really needs to do is reduce the T4 somewhat, and add in some T3.


Thank yoU greygoose my Endo said he wants to trial me on T3 but just wanted to run bloods with me on 100mcg first for 6-8 weeks. Could this be why I'm not improving and feel so sick and keeping getting thyroiditis flares? I feel no better now than when I was first diagnosed in March.

Also I keep seeing rT3 what is this and what does it mean? If I continue like this without T3 what could happen? Thanks


I would say that it would be difficult to improve with an FT3 that low. Most people need it up the top of the range to feel well.

rT3 is the body's safety valve. If you are in extreme conditions - sick or starving - the body will convert T4 to rT3, instead of FT3, in order to save energy and allow the body to heal.

The problem comes when the body has difficulty converting for other reasons - nutritional deficiencies, high/low cortisol, etc - and too much unconverted T4 builds up in the blood. In order not to waste the T4, the body will sometimes convert it to too much rT3 - which is later converted to T2, so it's not wasted - and the rT3 gets stuck in the T3 receptors. Because, then, the FT3 can't get into the cells. That's why you don't want to keep increasing the T4.

What will happen if you continue with this low T3? Well, you won't get any better, and could get worse, develop new symptoms, continue to put on weight. Every cell in the body needs T3, so it could affect organs like the heart, and the liver. Your brain needs more T3 than any other part of the body, so you could develop confusion, brain-fog, depression, etc. Nobody knows for sure exactly what would happen, but there are many possibilities.

Have you had your nutrients tested - vit D, vit B12, folate, ferritin - because if these are low, not only will your body be unable to use the T4 you're giving it, but they will also cause symptoms of their own.

OH! Just noticed that you have had vit B12, folate and ferritin tested.

B12 is a bit low - it needs to be at least 500.

Folate should be at least mid-range.

Ferritin is fine.

But, you do need your vit D tested. :)

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I have been supplementing since the tests above but again it's been making little if no difference to my health. I know my B12 was just over 500 recently as I asked for the B12 injection hoping that might help but it's the highest it's ever been as I'm taking vitamin supplements in the hope to improve my energy levels but even with a healthy clean diet and supplements I'm not improving. I'm just hoping I get T3 on prescription asap otherwise my only other option is to self medicate and hope my Endo & GP will support me if I can't get T3 through the NHS.

How can I increase folate? It seems to be the one I'm low in. Thanks


When were these tests done? If within the last couple of months, I'm not surprised the supplementing hasn't made any difference. All of this takes time! A lot of time.

If you are supplementing B12, there is no point in doing a serum test, the results will be skewed, and you will be none the wiser.

When you say you're 'taking vitamin supplements', what exactly does that mean? A multi-vit? or individual supplements in the right doses? You won't get anything out of a multi-vit.

As to diet, what you eat - whilst important in the wider scheme of things - isn't going to help how you feel if your FT3 is still too low. And, if you have low stomach acid - as most hypos do - you aren't going to absorb very much of anything from your food - which is why your nutrients are low.

How can you increase folate... Well, if you've been taking sublingual methylcobalamin (B12) then you should have been taking a B complex, which should have increased your folate, because it's contained in the B complex.


The photo was from may this year and I've been supplementing since. I take the vitamins which have been recommended on here which I also researched including B12 majority I've sourced off amazon. The only one I stopped taking g was selenium as I felt it triggered my thyroiditis flare so am too scared to take it again. I'm just wondering if supplementing and diet won't make much difference if I need T3? Which is why I'm not improving and my thyroiditis is evolving and getting worse. At present it feels out of control and although I'm trying to help myself I'm beginning to give up as I feel so tired & sick and catching any bug going. It's getting me down now and I just feel tearful constantly which isn't me I'm usually so positive. I'm just so tired. I've no fight left in me and am at a loss what to do. Week by week I feel my body getting weaker yet still no closer to feeling any better 😢


Because your T3 is too low. But don't give up on the other things. Everything needs to be optimal. But it all takes time. 7 months isn't long, in thyroid terms. Let's keep our fingers crossed that you get that T3!

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Thank you x


You're welcome. :)


Helllo greygoose just wondered if I could have your opinion on my latest blood tests as I've been on 100mcg for 6-8 weeks now and seeing my Endo next week? TSH 0.20 (0.38-2.5) FT3 5.0 (3.5-6.5) FT4 20.2 (10.0-18.7). My GP says he will prescribe T3 if I get my Endo to confirm this. As my thyroiditis is evolving my TSH will increase again as before but I'm on the max dose of Levo for my weight so I think T3 is what I need to improve. Thanks


Well, your conversion isn't brilliant, that's true, but there's no knowing how an endo will react to a request for T3 - they are a law unto themselves!!!

But, your weight has nothing to do with your dose of levo! Nothing at all. What's worrying is that you need it over-range to get enough T3 for it to be mid-range. Which means that there is a lot of unconverted T4 slopping around, which could convert to rT3. That's the problem. Nothing to do with your weight. And that's why you need some T3 added to a reduced dose of T4. :)


He's offered it to me at my last visit he just wanted to run another test before writing to my GP. So I don't think these bloods will make much difference especially not when my GP is supportive of me going on T3 also! Looks like I might finally begin to feel better once I'm prescribed T3 and can lower my T4 slightly. Many thanks


I'll keep my fingers crossed for you that it all goes smoothly! I'm sure you'll feel much better once you get your FT3 levels up a bit. :)


Thanks I'm actually excited maybe there is light at the end of the tunnel! Fortunately this forum has been here throughout this year or I'd have been at a total loss


There is, indeed, light at the end of the tunnel. :)

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Just as I get my TSH lower in increases again and I'm already on the max levo dose for my weight so it'll be interesting what my next bloods are I have done tomorrow


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