Thyroid UK
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Low TOTAL T3 on Eltroxin -significance?


I was diagnosed hypothyroid 4 years ago. A year ago my TFTs revealed normal T4 & TSH on Eltroxin 75mg daily. However, my blood test also revealed a low (abnormal out of range) TOTAL T3 - (free T3 not available). My endocrinologist completely dismissed it as meaningless and said it shouldn't have been ordered. She referred me to a rheumatologist for my ongoing muscle pains and spasms that have been getting progressively worse - I was seen by the rheumatologist who told me he 'suspects it is my thyroid' as he says muscle/joint pains are common in people with hypothyroidism even when optimised on Eltroxin.

My question is does LOW TOTAL T3 automatically imply LOW FREE T3?

I have searched forum and internet and all I can find is the insignificance of a NORMAL Total T3 - I can find nothing regarding significance or otherwise of a LOW TOTAL T3 in the context of HYPOthyroidism.

Thanks in advance :-)

9 Replies

Welcome to the forum, Waltzingfrog.

Total T4 and Total T3 are rarely used in the UK as Free T4 and Free T3 which measure the unbound T4 and T3 are seen as more useful. I don't know whether there is any significance to low Total T3. As you are symptomatic I would order a private thyroid test, including FT3, from Blue Horizon or Genova via If you post the results and ranges (figures in brackets after results) in a new question members will advise whether you are optimally medicated on 75mcg.


I am not a medical professional and this information is not intended to be a substitute for medical guidance from your own doctor. Please check with your personal physician before applying any of these suggestions.

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Thanks... Will do :-)


Blue Horizon - thyroid plus ten blood test will check TSH, Ft3 and Ft4, Plus both types of thyroid antibodies. also levels of B12, folate, and ferratin. .

Also good idea to check Vit D levels

See thyroid UK website for info on why vitamin levels are important.


Thsnks SlowDragon

I should have mentioned all my vitamin levels well within norm levels.. Vit D > 100 Except puzzlingly, my calcium low for years despite good diet plus supplements & normal Dexascan. Plan on bringing this up with privste endo after I get my bloods done with Blue Horizon.. Thanks again 👍


I would have a private Free T3 blood test as we cannot feel well if levo isn't converting as it should.


Thanks... Yes i have just ordered the Thyroid+10 online.. I will post up the results when i get them as it maybe of interest to others..

BTW i got 20% discount (£30) by adding 'best' to the coupon code box.. That might be of use to someone else on here :-)


That's an excellent discount.

Your could put up a new post saying how you achieved your discount as it will be lost in this post, I think :)


T7, TOTAL T3, TOTAL T4, UPTAKE, or any other thyroid labs: useless for our particular needs

1 like

Done 👍


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