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Thyroid UK
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New to site - hello!

Hello everyone! I'm new to this site and it seems from past blood tests that I am unable to convert T4 to T3. I am on Levothyroxine only, been taking it for 5 years and have never felt well on it. I am currently taking 75mcg Levothyroxine after many, many dose changes and looking for a source of T3. I believe I have been unwell since taking Levothyroxine and I do suspect I have been unwell with hypothyroidism before diagnosis. Any advice/feedback/support would be great. Thanks


TSH 10.2 (0.2 - 4.2)

Free T4 13.8 (12 - 22)

Free T3 3.0 (3.1 - 6.8)

13 Replies

Welcome Ceria, I’ve found this site very helpful. It’s all very individual. Good luck!


Thanks :) I hope to get good advice/feedback etc here


Results like yours would mean that I needed more Levothyroxine in the days when I could convert it. But I was never typical. I think a lot of people need free T4 towards the top of the range.


Hi, yes same for me. I have been on as much as 150mcg Levo at one time and my free T4 is at the top and my free T3 is at the bottom. I asked my endo why my free T3 is at the bottom and my free T4 at the top and he didn't know. I googled causes of poor conversion and it suggested secondary hypothyroidism but to have that I would need to have TSH below range or low and my hormones low.


You are obviously very under-medicated, based on the results you've quoted - your TSH is far too high. Some questions :

1) What is your doctor's excuse for not increasing your dose?

2) Has your TSH ever been lower than it is now?

3) Has your dose ever been higher than it is now?

And a comment :

You may well be right about not converting T4 to T3 very well, but until you get your Levo dose higher and get your TSH lower, and then see what your Free T3 and Free T4 are doing then, then you can't really conclude for definite that you don't convert well.


1) GP hadn't gotten back to me

2) yes

3) yes

When levothyroxine was raised T4 at top and T3 at bottom



Okay, so now I'm wondering why your Levo was reduced by half, since you've been on as much as 150mcg.


Due to past thyrotoxic results

TSH 0.03 (0.2 - 4.2)

Free T4 20.5 (12 - 22)

Free T3 4.1 (3.1 - 6.8)


Doh! Can you sack your doctor or endo, please! ;) Those results are not thyrotoxic, nor were you over-medicated.

The thing which makes people thyrotoxic or over-medicated is high Free T3, not low TSH - but doctors don't agree, sadly. Very high (over the range) Free T4 is probably best avoided too, but how you feel is more important than anything else.

If those results had been mine (I'm hypothyroid, I'm not medically trained), depending on how well or ill I felt I would have just added 5mcg or 6.25mcg of T3 (quarter of a tablet of 20mcg or 25mcg T3 tablet) to be taken in the morning. If you are from the UK you would almost certainly had to source any T3 online.

Then depending on how well I coped with that I would have added another 5mcg or 6.25mcg T3 later in the day - either afternoon or evening - a couple of weeks after the first addition. Then 6 weeks later I would have done a re-test. It may have turned out that a 25mcg reduction of T4 might be needed at some point, again depending on how well you were feeling and what your symptoms were.

An alternative to faffing about with T4 and T3 would be taking NDT (Natural Dessicated Thyroid), which you would also have to source online. Many people do well with the cheapest brands which are from Thailand. They are called Thiroyd, Thyroid-S and TR Man.

A dose of about 130mcg Levo is roughly equivalent to 2 grains of NDT.


Thanks! I am from the UK and I have never felt any relief in symptoms before or after diagnosis no matter whether my results are seen as optimal, normal, low or high. Symptoms list (unchanged since diagnosis)


Irritated feeling at front of neck where thyroid is

Difficulty swallowing

Swelling in front of neck which comes and goes

Joint pain

Weakness in legs

Heavy periods

Hair loss

Puffy face and eyes

Weight gain




Feeling cold

Flaky nails


Cholesterol deposits under and around eyes as well

Brain fog


Dizzy spells


Eyebrow loss

Trapped wind


Your list of symptoms is fairly typical of someone with untreated or poorly treated hypothyroidism. Some of the symptoms could also be caused by low nutrients.

Many people with hypothyroidism have lots of problems with their gut - low stomach acid, severe indigestion and/or heartburn, gastritis, IBS. All these issues may lead to poor nutrient absorption from food. Many of us discover that we have low vitamin B12, low folate, low iron and/or ferritin, low vitamin D. There are other important nutrients, but most of us start with the ones I've just listed, once we've tested and found out which ones are below optimal.

You should ask your doctor to test the things I've just mentioned - although a full iron panel is preferable to just testing iron or ferritin. If your doctor refuses to do any testing for you, then you will have to pay for your own (if you can afford it).

Some links for you :





You don't need to see (or pay for) a doctor or get a doctor's permission to get private testing done.

If you get testing done, before ordering tests post a new question and ask for info about how to go about it - timing, days of the week it should best be done, how to do it, making sure that meds don't interfere etc.

If you read some of the replies written by SeasideSusie you can find out the type of things that people can find out and learn from testing :



I have already had these done so will post. Thanks

1 like

Firstly you need an increase in medication which will take 6 weeks to fully get into your system and then retest again to see if you still need more. In the mean time get your folate, ferritin, B12 and Vit D tested and these need to be optimal not just in range. See SeasideSusie's posts for more info on that. You need to get your conversion wotkingvwell though anfcmany of us take supplements to ensure this but it takes months rather than weeks to address this ifclevels are low. Taking T3 before you do this can help but you need really to address the cause first and you may well find you don't need additional T3 orconly a very small amount. Hopefully though once you get your body working as it should you should be fine. Took me 5 months to reverse my problem and well worth the effort.


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