Help please!

Ive written before about my askew thyroid. Basically my TSH was high and my FT4 was also high. My endo was investigating and took me off Eltroxin. My regular dose prior to stopping was 100mgs m -t and 125mgs f-s. Im currently back up to 75mgs daily. Just got my blds done by my gp and here are latest results:

TSH: 49 (ref 0.3-4.2)

FT4: 21 ( 9-22)

FT3: 1.0 (1.3- 3.3)

Ive always felt im not converting and this obvs shows this doesnt it? My endo doesnt tell me actual results just says they are in normal range but i want to be forearmed for next appointment so appreciate any feedback from members who i feel are more knowledgeable than my endo. Does it appear T4 isnt working for me?? Would you suggest adding T3??

Thanks in advance,


20 Replies


Poor conversion is indicated by low TSH, high FT4 and low FT3. Your TSH and FT4 are both high. Your endo should investigate resistance to thyroid hormone and TSHoma which is a hormone secreting pituitary adenoma.

She says i have neither?? I had a brain mri 2 mths ago for another issue (developed double vision and 6th nerve palsy) and she looked at scans and saw nothing in pituitary area??


Okay MRI rules out TSHoma but it doesn't rule out resistance to thyroid hormone. How else does endo explain high TSH and high FT4 with below range FT3?

She said she doesnt feel i have resistance as my TSH has been dropping in response to increased doses of L4 but i find it strange my FT4 at upper range of normal at decreased dose of Levo nearly same as when i was on 100mgs???


The other thing to consider is heterophile antibodies to TSH. This may be the same as Diogenes is discussing. I don't think this will explain why FT3 is so low when FT4 is high though.

If interference to TSH is ruled out your endo should seek expert advice about resistance to thyroid hormone from Addenbrookes.

Is that in Cambridge??? She has sent my bloods to somewhere in Cambridge i think in UK


Yes, Addenbrooke's is in Cambridge.

She contacted them and sent my serum samples when i was off meds x 2 wks and they asked for more samples when i was back on 50mgs so ive more blds to do on 29th May and appointment 31st May with Endo

Was your test done at the very earliest, fasting and did you allow a 24 hour gap between your last dose of levo and the test?

If so, I think you may have a defective gene DI02 and I'll give you a link. If so you need T3 alone.

Actually no as i wasnt expecting gp to take blds so i had taken my eltroxin 2 hrs prior to these blds and had eaten toast....i shall get them repeated!!

Could be another case of artificially high TSH caused by test interference. Especially with FT4 as high as this which should have suppressed it. Get TSH done by another method.

No my TSH has been repeatedly high since jan and im on 3/4s of my original dose

But if the TSH is done by the same test then it still could be high artificially. A TSH as high as this and FT4 also high indicates something wrong with the TSH test method. Another TSH method should be used to check this out.

It was done in 2 separate labs in 2 major hospitals...TSH was 40 in one and 49 in the other..FT4 was 21 in 1 and 21.4 in the other

So did they use the same test from the same manufacturer? If so my suggestion stands. It is just that the combination of high TSH, high FT4 is very suspicious. I'd certainly try to get a TSH test done where the manufacturer is different from either hospital's. Perhaps the sources used here privately.

Oh right...not way or the other im extremely unwell with all this 15mths now and can barely fxn. Am getting weaker and weaker...cognition horrendous...can barely lift my arms...symptoms getting worse daily

Can i just say amazingly efficient replies and informed answers yet again from members on this are truly amazing !!

My results were similar, high TSH as well as high FT4, low convertion rate etc ... My endo actually stated that T3 medication can actually be dangerous! Full of lies and crap!!! Even though my Blue Horizons test showed this all is said was 'Some tests can show different results' .. Didn't really answer any questions. These are NHS specialists who take obscene salaries from the NHS .. Take that out of it and think about their training/medical studies AS A SPECIALIST .. I find it hard to believe that they do not know about low convertion, RT3 and dismissing more involved tests that help us .. THEY DO KNOW! They just choose to dismiss it so that they don't get in trouble with the NHS, putting their salaries in jeopardy ... All they care about is theirselves .. So good luck! Let us know how you get on.

Oh wow...tks for that reply...and how are you now?? What meds are you are? Did you feel horrendous? I actually feel like im dying from the inside out cos of course i look 'normal'....havent worked in 15mths...loved my job ironically in the medical field.. my life has completely dissolved around me! Hoping you are doing ok?

I have been trying T3 for the last 5 weeks or so, I do actually feel better, still tweaking the dosage but I'm not as tired all the time, less irritable, brain fog is clearing and I'm managing to loose weight! Lost a stone since Feb BUT lost the last 6lb within the last 6 weeks!! My endo can go and have intercourse with himself! He's about as useful as a chocolate fire guard!!

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