Thyroid UK
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High Free T3

I think Im panicking a bit here but as usual Im reading stuff on the internet and scaring myself.

I know some of you on here take huge amounts of T3, above what is recommended. Also that you have high T3 levels, presumably because thats what makes you feel better.

My Free T3 level has come back abnormally high and Ive been advised to reduce my T3. I had no symptoms of high T3, or I don;t think I did. I feel quite well at the moment even now that I haven't taken any T3 for 3 days now. I have to get it out of my body.

However, do I? My TSH is 6.8 and Im worried that it will raise by not taking the T3.

I suppose what Im saying is that as my T4 is low and my T3 is very high, as I reduce the T3 am I in danger of having no hormones left?

What is the reason for you taking high T3 and what are you doing about your levels being above range as are mine. In fact mine are hugely above range.

30 Replies

Hi, Numberone. First thing, don't panic. Nothing's going to happen tomorrow or the next day or the next...

Secondly, my guess is that this is the first of a long list of responses you are going to get. Some of the advice will probably conflict, so take a breath and work through what follows feeling for what is right for you. In a state of worry you could get driven hither and thither with choices.

Thirdly, there are reasons why some people take T3 only. It suits them because, for example, they can't convert T4 to T3 very well. Some people need to take T4 with the T3, either as a synthetic compound or part of the T3 naturally found in dessicated thyroid gland. Some people don't need to take T3 at all. And some poelpe find their body changes and they have to adapt the meds.

I've read your post that you want to document your journey through and you seem to me to be only on T3. That your T3 is very high but your T4 is low. Just a few things before you get far more in-depth replies; low T4 an cause symptoms of, but not actually, asthma. It can also cause the body to utilise noradrenaline because low T4 can affect the production of cortisol (their levels are proportional) and the body therefore resorts to noradrenaline, which will cause symptoms of anxiety, both physical and emotional. Low T4 means you have no reserve hormone for your body to make reverse T3 which prevents T3 from being active in the cells, so your T3 is high and engine is running hot - yet in some ways you are hypo too (low T4).

Have you tried natural dessicated thyroxine? As opposed to T4 or T3 only, I mean. As a starting point it might be helpful: you seem to need a higher ratio of T3 to T4 than some people, so the ratio of these in porcine thyroid gland may suit you, either alone or with top-up from either T4 or T3. Just a suggestion to start the ball rolling!

Either way, easy for me to say though it is - try not to worry too much. Your body's needs have changed and you've now got the job of tracking the changes and adjusting accordingly. I'm certain you'll get lots of advice, so all the very best to you. You'll get there.


P.S. If you feel well, why are you panicking at all? Is it the numbers?


I am panicking because of the numbers. They are extortionaly high and yet I thought I would sense if the T3 was too much....I haven't noticed and that worries me. Also the numbers were slightly high a few months ago and I cut my T3 down and yet its come back double almost. Im also panicking because I can't start fiddling around with the dosage as about to go abroad for a couple of weeks and I know I will worry.

Also panicking because anything that seems to happen to me is all related to unbalanced thyroid issues. For example I had a strange loss of vision in one eye and that was when I was first diagnosed. I have had this breathing thing which seemed to be thyroid related. I can whip myself into a frenzy and I know I'll now be worrying about the flight etc etc.

You say nothing will happen in the immediate future but once I start fiddling around with my dosage I know it will make me feel unwell and Im supposed to be going away, dealing with xmas etc etc.

I havent even had a racing heart or high temperatures, high pulse etc etc. So what on earth is happening with me. I thought they were all the symptoms of being overdosed. I also can;t get to the bottom of if the T3 is Free ie floating around, does it mean it wasnt that dangerous because it hasnt got into my cells and my TSH is still high. Also if my TSH gets higher, then I know I will start to experience some of the other stuff rather than feeling everything is ok.


If you are on T3 then the usual blood test results are not any use.

The numbers you have recorded are normal for you. I would be pleased with these numbers. I have been on T3 for nearly three years.


Hi Kathleen. Im interested in knowing why you would be pleased with these results. I know I can't read the results normally but the Free T3 is extortionately high! In what way can I be pleased with them or am I just being a scaredy.


Read 'Recovering with T3' by Paul Robinson. And join his helpful site as long as you are prepared to put in the homework in trying to get well.

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I ordered it yesterday. Thank you. Some light reading for Xmas.


I am now reading it for the tenth time and still finding useful things in it. On the forum he is very helpful also other admins. Best wishes.


But does it explain High Free T3 and a high TSH in comparison? So confused by it all and Dr Peatfield is in hospital.


Your numbers are, as you say, very strange. Do you have a thyroid?

I wonder whether you have some kind of thyroid hormone resistance. It seems you feel well with extremely high levels of FT3 and also feel well without taking any for a few days. FT3 only stays on your system for a day or two, so you won't have much left now.

I think a dodgy pituitary can give a false high TSH or a false low TSH, but even if we ignore your TSH reading it is still odd that you don't get hyper symptoms with an over-the-top FT3 level.

Weird. I bet your doctor/endocrinologist is confused.

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I'm away until after Xmas but have just booked a private T3 friendly endo from after. I wonder if I am Thyroid resistant? It's definitely a probability after all I've read now.


Hi what you have to realise is that blood tests are just a guide and nothing more. Don't take them literally as it's what is reaching the cells that matters. Test your pulse before rising, get a symptom sheet and highlight your symptoms, get your adrenals tested by a saliva kit, Genova do an adrenal test profile, it's not that expensive and get your iron tested, then you have the tools to move forward.

T3 surpesses TSH. Your TSH is too high accordingly to my Belgium doctor, he states nobody should have a TSH over 2 as in the long term it can lead to heart disease. I can post these findings if you want me to just let me know.

If you need anymore help then please ask.


Thank you. Are you saying that in this case, the Free T3 figure which indicates it isnt getting into my cells, doesnt cause so much of a problem? If thats the case I'll stop panicking but obviously there must be a reason while my cells arent receptive anymore? As Ive said previously I have had a change in other medication and for the last month I lost a stone in weight on a stupid diet. Could I have caused my adrenals to not work properly by that diet and end up not absorbing the the T3. It would appear something is stopping them when my TSH has increased to 6.85.


When I went to the USA for guidance from Drs Lowe my blood tests were fine but I was not. I literally ceased up with fibromyalgia. They took me off T4 entirely and put me on T3 only increasing by 6.25 mcgs every 5th day to "wake up" the receptor sites. This worked for me but it has to be done under medical supervision and I don't know anyone here that would do that. They ensured that my adrenals were fine before they started.

If your TSH has increased then you are not taking sufficient thyroid hormone. How much are you taking at present of T4 and T3? Have you had a saliva test done for your adrenal function?


I have only been on T3 for the last couple of years and previous results have been near enough fine. For some reason my cells don't appear to be receptive now.


Hi how much are you taking and are you taking T4 as well?


Hi. I was taking 37.5mcg having reduced from 50mcg about 4 months ago. I do not take T4 hence my very low T4 reading. I take the 37.5 in a couple of doses throughout the day. I feel well, do not have high temps or rapid pulse.


That could well be your problem taking in several doses but if you feel ok on it why panic or is it the blood tests that are making you panic? I would take your pulse before rising in the morning, try to keep as still as possible when taking it and if it's around 70 beats per minute and you feel fine then all is well. Symptoms are everything and pulse. TSH should always be under 2 according to Dr Hertoghe.

Drs Lowe always recommend taking in one dose as it stimulates the receptor sites instead of trickling it in but as I said before if you feel great then why worry.


did you take your meds before blood test hence it is advised with t3 meds to take the last dose the day before and take blood test the next morning before your meds hence since t3 goes into the blood system will falsely elevate your blood results on t3 but it usually suppresses tsh as well.......


No, I took my last T3 tablet the day before the testing. In any case, my TSH i high even though high T3. Does anyone think these results might be skewiff because it just doesn't make sense in my opinion.


hello are you taking t3 only?


Hi Bossbird. I have taken only T3 for about the last 2 to 3 years. It is because I felt so very ill on T4, could hardly move, felt puffy, pain in joints, couldnt lose weight etc etc. I was given advice on taking only T3 and decided to try. My own GP wont monitor me but I have the advice of Dr Peatfield and here if I have any problems. I felt like my life was given back to me once I started taking it. My results were never perfect, took a bit of fiddling about with dosage etc but always within ranges. This test has frightened me.


Thank you everyone. I am totally confused as is my Dr. The Dr has advised that I stop the T3 for a few days to clear it out of my system. I have done this and I have today introduced only 5mcg of T3 to start with because Im feeling tired and I know my T4 is very low so don;t want to run out of reserves. My results have never been like this in the past so I haven't a clue. I checked with Blue Horizon that there wouldn't be any mistakes with the blood test and they assure me there won;t be.

My last dose before the test was the day before so no issues there.

I know that it should be more about how you feel but why is that free T3 level so high as well as the TSH being high. It read as 22 ish when the top of the range is 6.8! I apparently have Hashimotos and I know that can skew results but by that much? Is the Free T3 ie that amount which is not being absorbed as dangerous as if it were into the cells?

My TSH is definitely too high. I try to keep it around 2 and a little lower. This has suddenely shot up. My last test ie 5 months ago, the TSH was 2 but the Free T3 was 12 and so I started reducing the T3 by almost half. What do I get? Higher TSH but also a higher Free T3!

So confusing.


Hi No.1 , I've just re-read your original post and hope this will help

1 suggest you also re-read the start yourself - you said you stopped taking the T3 for 3 days. Your TSH had always Been around 2, but then shot up! AFTER stopping? Admins here, whom I respect , say it takes around 6 wks for Levo dosages to affect the system.

i was self experimenting 3 months or more ago, and stopped for 4 days! To gauge what would happen. my TSH had shot up from 1.05 to 17.9 ! Then I went back on to 100mcg daily, blood test last week showed it was down to 12.something! Still high, but at least it had lowered.

Doc has just put me up to 112.5 Mcg , but again brain fogginess and lack of concentration! So I haven't taken any at all today. Just to even out what in my system. we'll see what happens at next blood test, although I suspect I don't even need as much as 100. My thyroid is shot now. I have an autoimmune condition, which I've discovered could be linked to other things going on in my body or it's definitely Hashis!

Some of your symptoms could also be put down to stress affecting your health and your endocrine system. Have you had a blood test for Vit B12? If thats low, as also discovered from here, it could be you need supplementing- but don't take any till you've had it tested, then post on here and you'll find out one way or another

So as others have said don't panic! Because you are concious of breathing problems, which may disappear quite soon or no.

As you are off on hols for Xmas, when flying, suck Strepsils, the pink one are sugar free. It helps with the cabin pressure on take off and landing, as well as stopping the germs floating around with the air conditioning blowing straight down on your head. I always used to turn it off, when I discovered my 'cure' for sore throats always turning into a cold! I've told several people to do that and they've said it stopped them getting bad throats or colds as well after flying!

Hope we hear you are back safe and well and feeling better than at present!

Bon Voyage and a Happy,Christmas :-) . X

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I shouldn't worry about your TSH levels , I was diagnosed with hyperthyroidism in April the doctor over medicated me and my TSH went to 86 , mind you I did feel pretty ill lol


How dreadful for you. You must have felt like death.


Hello numberone1 - I remember you from a few years ago :)

Glad you have been doing so well on T3, I would try not to worry about your results if you are feeling well and have no symptoms of over stimulation.

I am doing well on NDT - 2.25 grains seems to be the right dose for me. I had a surprise blood test a few months ago and had taken my full dose of ndt about 1.5 hours beforehand. My ft3 was about 18 I think! I had another test leaving a 24 hour gap and ft3 was back to 5.5ish (3.1-6.8). My TSH is suppressed though, so it is interesting that you have high ft3 and TSH.

i definitely think symptoms are a better indication than blood test results. xx


Hi Clarebear

Yes I definitely remember you. I think you helped me make the decision to see Dr P and also to try NDT (which didnt help) but T3 alone did. You can tell from my messages that Im a bit panicked by my latest results and mostly because I don;t understand them ie increasing TSH, High Free T3 and Low T4. I understand the T4 reading but the others don;t make sense. As a result I have taken extreme action ie not taking too much T3, not feeding the situation but also aware that it will probably increase my TSH figure too. I can't go to my GP because Im about to fly to NY for 10 days and so I have consulted with Paul Robinson and keeping an idea on temps etc. I definitely think some new medication im taking has something to do with it but I have to take that. I have also made an appointment with a private T3 friendly endo locally as my GP will have nothing to do with the T3 even though I felt my life opened up again as soon as I started taking it.

Thank you for your comments. I think it the TSH was really low, Id definitely worry about going hyper but as its increasing it can't be that. At the end of the day, maybe I have a pituitary tumour or I have Thyroid hormone resistance but Im sure I'll have to cross that bridge if it comes to it. Ive gone into menopause this year and that can't be helping either with all those raging hormones!


I bet you did Norah.........I took my 112.mcg today and definitely ' feel' different in myself, like I've changed a little.

It's so hard to describe how you 'feel' when it involves the brain and you are taking meds for thyroid!


When your TSH result is out of step with FT3/FT4, there are several possibilities.

The TSH test or level is being interfered with by something. Examples include antibodies to TSH, some medicines.

You could have a pituitary problem, such as a TSHoma, causing excess TSH to be produced.

Pituitary resistance to thyroid hormone (very rare). The pituitary carries on producing TSH because it is insensitive to the thyroid hormone in the bloodstream.

Resistance to Thyroid Hormone.

If it is interference, the standard protocol is to take two or three new samples at the same time and send them to labs known to use different technologies. If the results come out very similar, it is probably real. If they differ significantly, it is likely an interference issue.

TSHomas usually result in hyperthyroidism. However, the complexity of a TSHoma in someone who already needs thyroid hormones is such that I have no idea quite what would happen.

Sandy12 is the RTH expert round here and has lots of information. Maybe send her a PM? (She is just a sufferer - not a doctor.)


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