Thyroid UK
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T3 result

I have just had the report back from my blood test to test my level of T3. My own doctor does not check T3 so I have gone private and done a test. My result is 4.48 and for what I understand this is within the 'normal' range. From other users of this forum can I ask your opinion on this result. I am going to see my doctor on Monday where she will have my latest TSH and T4 result and I just wNted to ensure I am going fully armed with all knowledge. Thank you

5 Replies

If you post the ranges of the T3 it will be helpful to give a response. The reason is that throughout the UK labs have different ranges and it makes it easier to comment.


3.1 - 6.8 is what this lab States as the 'normal range' and my result was 4.8

Thank you for your help


Philly2478, if you left 24 hours between last dose and blood draw the result is good. You can extrapolate +20% to get an estimated normal circulating level of 5.76 which is well within the top third of range considered ideal.


Hello Clutter, yes I did indeed leave 24 hours from last levothyroxine and did blood test before taking next tablet as thanks to this forum link I had read the importance of not taking blood before leaving a 24 hour gap from last tablet. This site is so good in helping people to get the best answers and advice. Thank you for your reply


The most important question is : how do you feel? If you feel good, then that result is good for you. If you feel bad, then you need an increase. Blood tests are just a guide, they're not set in stone.


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