Free T3 Query

Ok - I have nearly gone through all of the hoops or should that be "appointments" required to say that the cause of my pain is not arthritis, connective tissue disorder, diabetic myopathy, sports injury, physiotherapy etc etc and finally I should be seeing my Endocrinologist real soon to discuss the possibility that I am not converting my T4 to T3 so will require a prescription to try NDT.

But before I do, my question to you very kind experts is this:

I was diagnosed with Hypothyroidism in 2009

They tested my Free T3 in 2012 - Results 4.4 (4.1-7.9)

Only told me I have Hashimoto's 2 months ago

Can my thyroid become sluggish resulting in not converting to T3 effectively any more?

I will be mean...requesting :D an up to date FreeT3 test as well as my Ferritin and a Saliva Adrenal Gland test to try and sort out WHY IN THE HELL I AM STILL SUFFERING!!!!

Sorry, rant over - any ideas welcome!

WoodElf x

13 Replies

  • My understanding is it's not the actual thyroid gland that converts the T4 to T3, it produces the T4 to be converted. You need all your other levels ( iron vit d vitb's etc etcetera) to be optimal to ensure good conversion, even then there are other factors that may hinder this.

    Hashimotos will damage the thyroid gland therefore hamper the production of T4. You will also benefit from a RT3 test doing if you can get one done.

    If I am mistaken, those with much more knowledge will be along shortly to point you in the right direction

  • Thyroid gland produces both t4 and T3, alone with t1 and t2, the t4 is later converted as well to t3 by other organs.

  • Ok that's great! So efecticely I suppose my question was is it possible that my body can stop coverting T4 to T3 then over time as my condition worsens?

  • Yes it's possible. But it's not connected to your thyroid itself. More so it's about your other organs and how well your body is functioning as a whole. If your condition worsens, most likely it is from these other factors, as when properly medicated with thyroid hormones you no longer take the thyoid's health into consideration as you are replacing that with the medication.

  • If you're not converting, one main reason could be vitamin deficiencies, it is important to have optimal levels in b12, vit D, ferritin, iron, folate. If these are low then you may not convert well.

    Please note doctors don't prescribe supplementation until you are surely deficient, so it would be a good idea to get these tests done and keep the results. Post the results here and members can help you optimize your levels.

    Is your FT3 result from before you started treatment?

  • It was just after I started my first course of treatment but I have now posted my other results but they wont do my FT3, Ferritin or Adrenal's. Vitamin D was 62 Range (>50nmol/L = Sufficient)

  • I understand some members pay of pocket to get these tests done. Since the FT3 was done before treatment it's not so useful in knowing if you're converting levothyroxine properly.

  • Hashi's people are often bad converters.

  • That is VERY VERY interesting thanks for that info Greygoose *thumbs up*

  • Woodelf,

    What makes you think you aren't converting? An FT3 test from 5 years ago is meaningless. Do you have recent TSH, FT4 and FT3 with ranges which you can post?

  • That's EXACTLY my point Clutter!!! They wont test my Free T3 because they say they have already done it?!!! They dont seem to understand that it needs to be done regularly?! I already posted my ranges TSH and FT4 and my GP has reduced my Levo without doing a FT3 test :(

    TSH 0.1 Range (0.4 - 5.0)

    FT4 18 Range (9-19)

    Since taking Jarrows B12 supplement:

    My B12 two months ago was 371 (160-800) and is now 883! Yeehaw!

    And Folate was 4.5 (4.80-19.00ug/L) and is now 12.5!

    I just feel like I am having a war and being a complete pain in the ar$e when I go to the doctors these days

  • Woodelf,

    Those results look good. I suppose your GP was concerned about the low TSH. A pity. You weren't over medicated because FT4 was within range.

    FT3 is rarely tested in primary care unless TSH is <0.03 because they are only interested in high FT3 indicating hyperthyroidism not potentially low FT3 in hypothyroid patients.

    If you want to know whether or not you are converting well you can order TSH, FT4 and FT3 privately via

  • Well I'll try again with my Endo (last time I gave him the benefit of the doubt) *slaps forehead* But this time we have evidence plus a bagful of tenacity!

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