Hi all, I think I may have messed up my latest blood test results by forgetting to stop taking my B vitamins (inc biotin) for the week beforehand - these results look very strange:
TSH 5.06 (.27-4.2)
FT4 11.4 (12.0-22.0)
FT3 4.5 (3.1-6.8)
I'm on 50mcg levo; NHS tests in January had TSH below 1 and FT4 just above midway in range; private tests at start of March had TSH creeping up at 3.17, FT4 a bit lower in range at 13.4 and FT3 at 3.91 (ranges as above). I should have gone back to the GP then, but couldn't face another difficult conversation with little prospect of getting an increase in dose. And I had a busy time coming up at work so decided to wait in the vain hope that the levels might sort themselves out (wishful thinking, I know...). Symptom-wise, I am feeling better than in January but still not symptom free; am gluten free, supplementing relevant vits and mins, and have found taking an adrenal cocktail has helped. Was thinking of self medicating to top up my levo, hence doing these latest tests, but I can't make sense of the results and now wonder if it's because I forgot to stop the biotin. Or could there be another reason? Grateful for any thought before I either re-do the tests or steel myself to go and see the GP... Thanks in advance!
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You are underdosed to have everything below 'range'. You need an increase of 25mcg now and a blood test in six weeks with another increase, I should imagine, until your TSH is 1 or lower. Your FT4 and FT3 are below range, so you must be feeling awful.
50mcg of Levothyroxine is a starting dose, with a 25mcg increase every six weeks until your symptoms are relieved and you feel well.
Thanks, Shaws. What seems strange to me though is that my FT3 is in range at 4.5 (3.1-6.8), even though the others are out of range. That's why I wondered if I'd messed up my tests by taking biotin as my FT3 is better than last time even though TSH and T4 are worse. Am I right in thinking it's strange for FT3 to be in range when the others aren't?
I was started on 25mcg and had to really push to get an increase to 50, as after 8 weeks on 25 my results were back in range so the GP saw no need for an increase. The usual story it seems!
No, it's not strange. The high TSH is pushing conversion to keep you alive. But, that cannot go on forever because your FT4 is low. Gradually, the FT3 should drop - it's already too low - and the TSH will rise.
If it helps when biotin messed up my results, my TSH was much lower than it should have been and T4 and T3 higher than they should have been. Given your previous results it doesn’t look like the biotin has affected these ones to me. It just looks like you’ve become more hypothyroid.
Thanks for sharing your experience. At least that tells me these aren't wasted tests! Time to go and see the GP again and hope they are willing to help!
Dr Toft, past president of the British Thyroid Association and leading endocrinologist, states in Pulse Magazine,
"The appropriate dose of levothyroxine is that which restores euthyroidism and serum TSH to the lower part of the reference range - 0.2-0.5mU/l.
In this case, free thyroxine is likely to be in the upper part of its reference range or even slightly elevated – 18-22pmol/l.
Most patients will feel well in that circumstance. But some need a higher dose of levothyroxine to suppress serum TSH and then the serum-free T4 concentration will be elevated at around 24-28pmol/l.
This 'exogenous subclinical hyperthyroidism' is not dangerous as long as serum T3 is unequivocally normal – that is, serum total around T3 1.7nmol/l (reference range 1.0-2.2nmol/l)."
You can obtain a copy of the articles from Thyroid UK email print it and highlight question 6 to show your doctor please email Dionne at
Thank you. I know I should have gone back to the doctor after the last tests really but at that point couldn't face doing battle with them again...silly of me, I know. Will definitely go now!
Just be confident. Say you need a 25mcg increase as you need your TSH at 1 or lower (he/she will be suprised as I believe they think a TSH somehwere in the range is fine). If he/she queries your statement say you are a member of Healthunlocked Thyroiduk.org.uk and this is what is recommended to get you on the road to recovery.
They do not know any clinical symptoms which should be relieved with an optimum dose. So also tick of your symptoms below and state you need increases until your symptoms are relieved:-
If it was the biotin that was the issue then surely only your last test could be iffy so suggest undermedicated so ask for an increase of 25 and take it from there.
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