Those of you who have conversion problem

Did you ever feel well on thyroxine only?

Just got my results back today

TSH 0.05 (0.35-5.50)

Ft4 19.4 (10-19.8)

I think doctor wants to reduce meds tomorrow. Plan is to try to get approval of 50/75 alternate days. I still feel ill. But felt good for 3 weeks when I had been on this dose for 1 week. I'm just worried that I have a conversion problem.

20 Replies

  • lisan1 You'll only know if you have a conversion problem if you have FT4 and FT3 tests done at the same blood draw.

  • without a result for free t3 no one can tell

    you also need results for




    vit d3

    all must be halfway in their ranges for any conversion to occur

  • The vits are good. But I was supplementing with a multivitamin when they were taken a maybe a bit skewed.

  • Hi,

    almost all multi vitamins contain iodine,which you shouldn't take if you are on thyroxine, so that may have affected the results.

  • Kent Holtorf has a good write-up on thyroid conversion problems. You can Google it.

  • Hi Learner 1,

    thanks,that's very interesting.

    In one of his papers he says that people with inflammatory conditions - including Hashimito's - will have a decreased T4 to T3 conversion,and because of this the TSH will be suppressed,making it an unreliable indicator of normal tissue thyroid levels. So any person with an inflammatory condition will have diminished levels of T3 and effective treatment must include T3. Also a suppressed TSH is not necessarily an indication of excess thyroid treatment.

    I will take this to my doctors appointment tomorrow, and see if it helps to get my T3 back!

  • Right!

    Also, look up what Jeffery Dach MD has to say about suppressed TSH.

    For some reason, I can't paste links here, but it should be easy to find.

  • Thanks!

  • Thank you for your replies. I have results of all from before diagnose.

    TSH 4.26 (0.35-5.50)

    Ft3 3.8 (3.5-6.5)

    Ft4 11.7 (10-19.8)

    Does that help at all?

  • That just looks like too low a dose. Both T4 and T3 are low in range.

    The problem here is that TSH is no guide once you are on hormone replacement. FT3 is the only meaningful figure.

    Low vitamin D can make you feel rubbish, as well as undermining conversion. You really need the full thyroid panel described above for a complete picture.

  • Thanks, but these were before levo. Before diagnose.

  • Ah! In that case you need to test!

  • You do not appear to have ever had thyroid antibodies checked. There are two sorts TPO Ab and TG Ab. (Thyroid peroxidase and thyroglobulin) Both need checking, if either, or both are high this means autoimmune thyroid - called Hashimoto's, by far the most common cause in UK of being hypo.

    TPO is rarely checked and TG almost never checked. More common to have high TPO or high TPO and high TG, but negative TPO and raised TG is possible, though much rarer. There are a few members on here that have this, often they have struggled to get diagnosed.

    ALWAYS Make sure you get the actual figures from tests (including ranges - figures in brackets). You are entitled to copies of your own results

    If you can not get GP to do these tests, as well as the vitamins (as outlined by @reallyfedup123), then like many of us, you can get them done privately

    Blue Horizon - Thyroid plus eleven tests all these.

    This is a finger prick test you do at home, post back and they email results to you couple of days later. Usual advice on ALL thyroid tests, (home one or on NHS) is to do early in morning, ideally before 9am. No food or drink beforehand (other than water) If you are taking Levo, then don't take it in 24 hours before (take straight after). This way your tests are always consistent, and it will show highest TSH, and as this is mainly all the medics decide dose on, best idea is to keep result as high as possible

    If you do have Hashimoto's then you may find adopting 100% gluten free diet may really help reduce symptoms

  • You say you still feel ill? What are your symptoms? Tiredness can feature when under and over treated.

    Given that you felt good for the first week on the dose increase could possibly point to being over treated for you....though technically your Ft4 is in range -just! Alternating like your planning on suggesting doing could make a difference and worth trying. Good idea. If you think about it 50-75mcg though a standard dose increase is actually a big increase relatively speaking.

    As far as conversion is concerned you do really need both ft4 & ft 3 doing,,,,what they call a full thyroid panel. Generally GPs find it difficult to get a Ft3 done as the labsfrequently ignore their requests. You can get them done privately to check this. Blue Horizen do them. Its difficult to tell from your blood test that diagnosed you.

  • It will be worth saving up to get the tests done as until you have them all you have no idea what you are dealing with and sadly neither do many doctors. FT3 reading tells us so much more and without it it's not really good to try and second guess.

  • TSH becomes irrelevent when at low levels.

  • I never felt well on T4-only. When a GP first put me on thyroxine (when I was really ill with intestinal permeability and crashed nutritionals), I would immediately feel better after starting it, then start feeling very anxious and hyper after maintaining a dose for a while, and have to go off T4 again. This yo-yo effect went on for a long time. After that, I was on T3-only and felt quite well (for me, T3 is a much "smoother" hormone than T4). Now, I am on T3+T4=10+75 mcg daily, and doing well with that. I absolutely need T3 10mcg to keep my FT3 at least 50% up in its range. However, I am running my FT4 ~15% up in range and if I attempt to raise T4 from 75mcg to 100mcg, I soon feel hyper and horrible.

    I don't know if my case is unusual. I've heard of people who can raise their FT4 up to range top, tolerate it, and still not be producing enough T3. But, I have never come across a case where the patient's system hates T4 so much, that the patient can only tolerate FT4 low in range. I know there are a few patients who only feel well on T3-only, but I don't know what the underlying biochemical reason is, other than rT3.

  • Thank you all for your advice. My doc agreed to take 50/75 and will do all the bits next bloodtest. How long will I need to be of supplements (b12, folate, vit d, ferritin) before test?

    Again, this site is the best for understanding thyroid disorders and getting help from all you lovely people.

  • Fingers crossed this dose will even things out for you🙂

    As regards supplements, b12 takes months to clear from the blood and the advice is that if you are supplementing then the tests are not useful to identify true deficiency, they only show what is in your blood from the supplement. As for d3 and iron, I have previously been advised to not take for a few days and I tend to stop 7-10 days before the blood draw. I read somewhere very recently that folate levels are used up pretty quickly but equally, if you have a high folate containing meal before the test then the results will be skewed, I.e. It will reflect what you ate and not what your levels are on average. I'd suggest stoping the supplement for a few days also.

  • Thank you so much for your help!

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