Very good levels of total t4 but ft4 and ft3 low, can anybody tell me why?

Hi all, I hope some of you out there can help. Over past few months I have been doing everything I can to up my Vit D, B12, Folate and Ferritin all were on the low side after my last BH blood test. Im not on any thyroid medication as my doc says Im normal! My tsh was 4.1 my total t4 117. (68-145) my ft4 16.8 (12-22) ft3 4.1 (3.5-6.8) so Im confused my frees are low but my total t4 seems pretty good? Im considering self medicating but I have been putting it off as to be honest Im scared of making the wrong decission. Should I consider NDT or because my total t4 is quite high should I be thinking t3? Any advice appreciated as no matter how much I read I cannot decide what to do. I have a long list of thyroid symptoms and have been ill for 4 years so I think its time I did something about it.


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14 Replies

  • magsyh What is the range for TSH. Your level may be very close to the top. Has it been rising over time?

    Have you had antibodies tested?

    Your total T4 is middling really, just over half way through it's range. Your FT4 is close to the bottom third and your FT3 is in the bottom quarter. So it would seem your TSH is far too high and your free Ts too low.

    Before self medicating, have you thought about seeing a good, thyroid friendly endos privately? You can email and ask her to send you the list of thyroid friendly endos. Choose whoever you can travel to and ask members for feedback.

  • Upper level for tsh was 4.5 I have seen quite a few gps, an endo and even saw a Harley St doc privately. All dismissed my symptoms and told me I was normal. I have done so much research, Im even doing an advanced nutrition course to help me work it all out. Its so frustrating! Im in Scotland so dont know if we have any thyroid friendly endo's. I have a bad sinus infection at the moment on my second lot of antibiotics and my cheek pain still driving me crazy so I have put off my next BH test till I at least feel better so that my levels are not all to pot due to inflammation. Thank you Seaside Susie

  • magsyh I've just looked back at your previous threads and see you've already tried NDT in the form of Thyroid S.

  • Yes I tried thyroid S back in aug / sept. Scared the hell out of me on 1/4 grain twice a day. It was then I had my bloods done at BH and discovered my vits were much too low. I have been supplimenting since oct and hoping for another BH test soon to see if any difference

  • As far as I know, the total Ts (total T4 and total T3) are useless as - unlike the free T4 and free T3 - they don't tell you how much of the hormone in question is actually available to the body on cellular I would not care too much about total T4 levels.

    Your TSH is highish as an optimal TSH when optimally treated with thyroid hormone treatment should be around 1 or lower, with FT4 levels in the upper third of normal range or even close to upper normal limit...if you take T4 drugs only, your FT3 levels should not be below midrange in any case, or you might have a conversion problem.

    So, IMHO, your TSH is too high, meaning you need to take more thyroid hormone medication. Unless you have taken optimal doses of T4 drugs only, you cannot know if your body is able to convert FT4 to FT3...the latter being the truly active thyroid hormone. Some seem to do fine on T4 drugs only, and they therefore must be converting enough T4 to T3. Others, like me, don't fully recover until we add T3 to the mix, no matter how much T4 we were previously taking. I, for instance, took 200 mcg daily for years (which most mainstream doctors consider to be a huge dose) without any noticeable improvement.

    If you cannot get your FT3 levels to rise even if you increase your T4 meds, you should indeed consider taking either synthetic T3 (along with T4 meds) or switching to NDT...

  • So anna69, are you suggesting that a conversion problem can still be assisted with straight t4? I'm interested because I'm having a similar concern as the initial poster, magsyh: low FT3, sorta low FT4, but being told I'm ok or that I have a conversion problem needing t3 only. So Idk whether to increase the t3 or try straight t4. I don't know if I'm misreading, but it seems like you suggest to magsyh to take t4? And if that doesn't work add some t3? How will she/he know whether she's/he's taken enough t4? Or t3? Your comment is really helpful. As magsyh question is often treated with straight t3.

  • No, if you have a conversion problem (that is, are not converting enough T4 to T3), taking more T4 won't help as that only increases the risk of reverse T3 (rT3) dominance. That means that excess T4 that cannot be converted to free T3 is instead converted to rT3 as a way for the body to rid itself of unwanted T4...rT3 and FT3 compete for the same cell receptors and high levels of rT3 can keep your FT3 levels suboptimal.

    Just to sound less categorical: some will tell you that you should look at optimizing vitamin and mineral deficiencies (selenium, vit B12, iron, ferritin), and treating adrenal fatigue before trying T3, as both vitamin/mineral deficiencies and low cortisol levels will affect T4 to T3 conversion.

    You cannot know if you suffer from rT3 dominance unless you have your FT3 to rT3 ratio tested:


    There is no way of telling you "this is when you are on enough T4 and/or T3". It depends on symptom relief more than labs (although most conventional doctors will not agree with that statement). The hormone levels that make YOU feel optimally treated without lingering hypo or hyper symptoms may be very different from the levels that are optimal for ME.

    Personally, I tend to feel well with a lowish FT4 when on NDT, provided my FT3 levels are in the upper quarter of range. The need for T4 naturally diminishes when you take synthetic T3 or NDT (which is approximately 20% T3), as the role of T4 is to be converted to T3 in the body. I have experimented with various doses and, if my FT4 levels are midrange or slightly higher on NDT, I feel less well than when my FT4 levels are close to the lower normal limit (I feel best when FT4 levels are 0.9-1.0; ref 0.8-1.5). I think this is because higher FT4 levels increase T4 to rT3 conversion, and the increased rT3 levels in turn make the FT3 work less well... I hope this was understandable.

  • Had my antibodies tested twice they were very low.

  • a tsh of 4.1 is in no way normal its hypothyroid and your thyroid is struggling

    a healthy person has a tsh of 1.0 or below and free t4 and free t3 in bala ce near top of their ranges

  • As both FT4 and FT 3 are low and TSH high you need to be taking more medication to get your FT4 and FT3 in the upper third and that may show a conversion problem but I suspect a higher dose my get you there.

    They was a mention that you had tried Thyroid S and struggled so was that before you looked into improving your Vitamin levels. The vitamins etc are important which ever course of treatment you do. Ah just reread and seen it was. But at least you are working on that.

  • The Total T4 is a measure of both the bound plus the Free T4 in your blood stream. Your body can only use the Free T4. The bound T4 will just be excreted. However, the TT4 test doesn't tell you how much of each there is, so it's absolutely useless as a test, and doesn't give you any useful information. It's the FT4 number that counts.

  • Thank you greygoose. I was trying to work out why so little ft4 when there seemed to be plenty bound t4. I thought there was perhaps a conversion problem I was missing. Thank you for clarifying Im barking up the wrong tree 😊

  • You can tell a conversion problem by comparing your FT4 with your FT3, but both your Frees are too low for a slight conversion problem to show up. You don't seem to have a major one.

  • Ughhh! I feel for you. Your question is essentially mine too. I've been taking t3 only, even though it's a low dose, with no improvement. I'm American living in Houston Texas. I read that you are in Scotland, so pardon me that I'm unknowing, but is T3 available there? Have you tried it by itself? You may have answered these questions on another board. I will check to see. I hope you are getting better.

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