Blood Test Results Showing High Reverse T3 - Thyroid UK

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Blood Test Results Showing High Reverse T3

Starahelm profile image

Hi. I'm new to these forums and have never made a post before.

My GP has prescribed Levothyroxine at 100mcg for several years now, and throughout that time I have never felt energised, or had any weightloss without major effort on my part - 40 minutes of fast cycling on my exercise bike while sticking to a low calorie diet.

I've tried to discuss this with my doctor, and have presented evidence gathered online to show how T4 may not be converting to T3, etc. but at the last session he lost his patience, almost accused me of arguing against science with black magic and quackery, and refused to accept that T4 wasn't the be all and end all for treating hypothyroidism.

I've now had a private test done (£170) and the results are as follows:

Thyroid Function

TSH 2.87; range 0.27 - 4.20 IU/L

T4 Total 127.4; range 64.5 - 142.0 nmol/L

Free T4 18.87; range 12 - 22 pmol/L

Free T3 4.08; range 3.1 - 6.8 pmol/L

Reverse T3* H 40.0; range 10 - 24 ng/dL

Reverse T3 ratio L 6.64 >20 Ratio


Anti-Thyroidperoxidase abs 12.0 <34 kIU/L

Anti-Thyroglobulin Abs 11.9 <115 kU/L


Vitamin D (25 OH) L 46 Deficient <25 nmol/L

Insufficient 25 - 50

; Consider reducing dose >175

Vitamin B12 388 Deficient <140 pmol/L

Insufficient 140 - 250; Consider reducing dose >725

Serum Folate 19.99; range 10.4 - 42.4 nmol/L

From these results it looks like the reverse T3 is pretty high, while everything else is within range.

I intend to present these to my GP, but I'm not sure what I should be saying to him, and what a high reading of RT3 means, if anything, with regards to still feeling like I have hypothyroidism. How do these numbers look, and is there anything I should be saying to my GP that contradicts his stance on the issue? Any help would be greatly appreciated.

34 Replies
SeasideSusie profile image

Hi Starahelm and welcome

I can't help with reverse T3 I'm afraid but I'm sure someone else will come along with some advice.

As for the rest:

Good news - your antibodies are low so do not indicate autoimmune thyroiditis (Hashimoto's disease). One less thing to worry about :)

B12 is too low. The Pernicious Anaemia Society recommend 1000. You can supplement with Jarrows or Solgar sublingual methylcobalamin lozenges 5000mcg daily, and in a couple of months, when level is nearer optimal, reduce to 1000mcg as a maintenance dose.

When taking B12 you need to take a B Complex to balance the B Vits. Thorne Basic B is a good one and contains 400mcg folate which will help yours which is a bit low, it needs to be at least half way through range, ie 26+.

Vit D is low, needs to be 100+. Supplement with D3 and also take K2 or a K Complex which includes K2. Vit D aids absorption of calcium and K2 directs calcium to bones and teeth rather than arteries and soft tissues.

If you get all your vitamins and minerals at optimal levels it will help thyroid hormone to do it's job properly, ie help convert the T4 to T3 which is the active hormone. Your conversion, at the moment, isn't too bad but could be better. For normal converters the ratio should be FT4:FT3 - 4:1 or less. Yours is 4.6 so you might feel better if your ratio was less. It's possible optimal vits and mins will help there.

A treated hypo patient generally feels best with a TSH around 1 or below or wherever it needs to be for FT4 and FT3 in the upper part of their ranges. So your TSH is too high at 2.87. An increase in your Levo would bring that down and increase your FT4 and FT3 to higher in their ranges. I would try for a 25mcg rise, if GP is not willing then maybe compromise on 12.5mcg.

Here is some evidence that may persuade him, it is from a Pulse article written by Dr Toft who is past president of the British Thyroid Association and a leading endocrinologist so maybe that will hold some clout when discussing with your GP.

"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)."

If you email she will let you have a copy of the article which you can print out and show your GP.

At the moment, whilst you are not optimally medicated, exercising to lose weight is pretty pointless. You have a better chance of achieving weight loss when on the correct dose of Levo. Also, exercise will deplete T3 (and you don't have too much of that at the moment) and make you feel worse so you might want to ease up on fast cycling at the moment.

Hi Susie and thanks for the response. I'll certainly bring up the level of Levothyroxine with my GP when I go in this week. I may try an interim amount, about 112.5mcg rather than going up to 125; when the doctor was trying to get my dosage right in 2007, he put me on 125 for a few weeks, but I had constant palpitations, which disappears instantly when he lowered the dose.

I had a feeling vit D was going to be very low, as I work mostly indoors. I must make a bigger effort to get outside and enjoy what little sunlight we've had so far.

I will contact Louise and request a copy of the article to help with the figures. If the GP still insists everything is right and gets irate again, I'll look at joining another practice - something my wife has already done for unrelated reasons.

Once again, thanks a lot for your help and advice.

ovsa profile image
ovsa in reply to SeasideSusie

hi. please if you don't mind could you explain a bit more about exercise depleting t3. thanks

SeasideSusie profile image
SeasideSusieAdministrator in reply to ovsa

ovsa I can't fully explain, I only know from what I've read. Have a look through some old posts that talk about it

ovsa profile image
ovsa in reply to SeasideSusie

thanks. still cant make out should one take extra t3 when exercising?

SeasideSusie profile image
SeasideSusieAdministrator in reply to ovsa

ovsa What sort of exercise are you talking about? Past posts have mentioned about excess or hard exercise depleting T3, obviously a stroll with the dog or something similar doesn't come under that.

Your rt3 is the way too high. In cellular level you are hypo as rt3 blocks t3.

Converting T4 to rt3 is very genius process from human body not only signaling that things are going wrong but forcing you to slow down in order to protect you.

Instead upping levo you would need t3. Plus you need to up your calories to prevent T4 converting to rt3. If you are starving yourself it turns on self protection mode slowing you down. You need good fats and good carbs.

Starahelm profile image
Starahelm in reply to Justiina

Hi Justiina and thanks for the response.

I intend to bring up the level of rt3 with my GP. I've asked him to trial me with T3 before but he just got angry, as though I was questioning his knowledge. That's why I thought I'd get a test done properly to have my actual figures available from a reputable lab to back me up.

For many years I have tried to lose weight, and have spent several years limiting my caloric intake while exercising. I have had limited positive results, but of course after a few weeks the low energy and exhaustion kick in and then the weight goes back on.

I was diagnosed as T2 Diabetic this April, so I have spent the last 2 months following a LCHF diet, which not only has seen my blood sugar levels reduce from 16mmoL down to avg 8mmoL, but has also made my joints feel far better. While the scales haven't moved, I did notice last week my shirts felt a little bit looser, so maybe that's starting to have some effect despite the rt3; I can't say I feel any more energised by it though.

Justiina profile image
Justiina in reply to Starahelm

Ok with T2 diabetes low carbs seems to do the trick with some. Still enough calories are required to optimise thyroid. Eventually that plus optimised nutrients and meds should do the trick and losing weight should happen.

To be healthy you don't have to lose weight but in order to lose weight you need to be healthy.

Human body can be very stubborn and resist weight loss and tries to bounce back to old weight. It's a process as you kinda have to teach your body new tricks. They say if you manage to lose weight and keep it lower, after a year the fight gets easier.

But first you need to get everything optimised and restore your health. You have gotten all good advice from clutter and gray so you are in good hands :)

Starahelm profile image
Starahelm in reply to Justiina

I agree. There's been some great responses, so a big thank you to everyone. :)

It's your doctor that's the quack! He knows nothing about it. So, I really don't think there's any point in showing him these results - unless you want to be forced to change your practice! Everything is in range - albeit rather low in range - and that's all he cares about. He doesn't know any better. No point in saying to him that you're not converting and your B12 is low.

But, you're right, you aren't converting very well. And that is probably due to your low nutrients. They all need to be optimal for your body to be able to use the hormone you're giving it.

I wouldn't worry about the rT3, that's a bit of a red herring at the moment. But, you certainly don't want anymore levo! Unconverted levo floating around causes trouble! You either need to reduce it, and add some T3 - as Justina said - or go onto T3 only whilst you supplement your nutrients up to optimal. And I can't see your medieval doctor agreeing to either of those solutions! In fact, I think you'd have a job finding a doctor that would, these days. The other solution is to buy your own, and self-treat, like so many of us do.

With a vit D that low, I really don't think just going out into the sun is going to help. You really need to supplement - and also take some vit K2, magnesium and zinc. SeasideSusie explained about the B12 and folate. But where is the ferritin result??? If that's low, too, you're not going to improve, whatever you do. :(

Starahelm profile image
Starahelm in reply to greygoose

Ah apologies; I thought I'd added the ferritin with the others:

Ferritin 92.1; range 30 - 400 ug/L

Thanks for the response greygoose. My feelings regarding the doc are pretty similar. I wanted to give him this last chance, and if needs be, at least I have these results to take elsewhere. I guess the problem there is where could I go when this subject seems to be treated by the medical profession as heresy that prompts draconian punishment?

I have read about people self-medicating, but have absolutely no idea about how to go about it safely. It's something I need to look into. The scare I had when my levo was at 125mcg leaves me feeling very cautious about playing doctor myself, but it may come down to it due to the medial profession's own rigidity.

greygoose profile image
greygoose in reply to Starahelm

You probably had a scare when you went up to 125 because of your low B12 and D. Your ferritin is fine, which is good! But you do need to supplement the others. Nothing is going to work properly until they are optimal.

Are you prepared to go private to find a good doctor? If so, email

and she will send you her list of decent docs.

Starahelm profile image
Starahelm in reply to greygoose

I would be most interested in going private, so I'll certainly send Louise an email. As I said, I see my GP this week. I will go armed with these results, along with anything else to back up what is being said here. He can either accept things need acting upon, or he can stick to his position. Either way is fine by me at this stage.

Once again, thanks for your help and advice.

greygoose profile image
greygoose in reply to Starahelm

You're welcome. :) And let us know how it goes!


High rT3 is usually caused by a build up of unconverted thyroxine (T4). Increasing Levothyroxine dose is likely to make it worse. I would be very surprised if your GP knew anything about high rT3, it isn't something which is tested on NHS. Usual advice to reduce rT3 is to switch to Liothyronine (T3) only for 3-4 months.


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.

Starahelm profile image
Starahelm in reply to Clutter

Thanks Clutter. That's great. Is Liothyronine available on the NHS, and is it something GPs are allowed to prescribe as an alternative to levo?

I had a feeling from the results that the rT3 level was likely due to a low conversion rate for T4 -> T3, sort of acting like a dustbin lorry collecting all the T4 rubbish lying around the body's highways.

To be honest, when I started mentioning T3 and T4 to my doctor, he looked totally gobsmacked. I guess we're all supposed to just take our medicine and go away. I don't mind doing that at the start, but if conditions don't improve, we have to have the right to ask why and demand a more thorough investigation. I'm sure some doctors welcome the interest, but mine seems to think any personally done research is, by default, rubbish - the result of erroneous advice arrived at due to the ineptitude of the patient to properly research their own condition.

Clutter profile image
Clutter in reply to Starahelm


Liothyronine can be prescribed on the NHS but due to it's extortionately high cost a lot of CCGs have banned GPs from prescribing. Many CCGs require an endocrinologist's recommendation before they will let GPs prescribe T3.

rT3 is the body's brake on over converting T4 to T3. Most hyperthyroid patients will have very high rT3. It won't be high due to poor T4 to T3 conversion.

I'd be surprised if your GP was able to advise you about high rT3 so you'll have to do your own research. Enter "reverse T3" into the Search Thyroid UK box top right of the page and Google it. Sites like Stop the Thyroid Madness, Paul Robinson and TiredThyroid are helpful.


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.

Starahelm profile image
Starahelm in reply to Clutter

Yes I was just looking at another thread on Health Unlocked from 3 years ago, where people were being told it was no longer available by their GP's.

I've sent Louise an email for private doctors willing to help. If, as seems highly likely, my next GP visit is not fruitful, I'll look into the possibility of going private. I'm unsure of the costs involved with that (not the appointment, the ongoing cost of medicines). I'll have to make a decision regarding cost if I reach that point. Meanwhile, I'll look into buffing those vitamins :)

Clutter profile image
Clutter in reply to Starahelm


In addition to the private doctor's fee you will have to pay for blood tests and prescriptions. A private prescription for 28 x 20mcg Liothyronine is something like £250 per month. 100 x 25mcg Turkish T3 without prescription is £20.

Blue Horizon and Genova offer a range of thyroid blood tests. You will need TSH, FT4 and FT3 which I think may be Blue Horizon Profile 6 but there are more comprehensive tests via

Starahelm profile image
Starahelm in reply to Clutter

Thanks for that, Clutter. These results come from a Blue Horizon test. £250 a month is pretty steep, especially with my wife now on disability. Is there any major difference between prescription T3 and the Turkish one, other than price?

Clutter profile image
Clutter in reply to Starahelm


Mcg for mcg I find no difference between them. Greek T3 Uni-Pharma is very popular with members and is similarly priced to Tiromel.

Starahelm profile image
Starahelm in reply to Clutter

Thanks for that, Clutter. Fasting now for another blood test before work tomorrow. I'll research these when I get home. :)

You most likely do need the T3.

It's over the counter in Europe and not a dodgy drug that the NHS seem scared of. Not just the price, imo.

Tricky to take, though - as you need to watch daily rising am temps, BP and weight.

Slow start and roll off of using it is needed. [P Robinson stresses this starting with 5 or 10 and raising every 3 days, or so].

Best if you get a referral though as I'm not saying what will work or not work for you -and I waited till I got support in NHS.

That will vary for you, depending on condition a lot- and in where you live, too..

Starahelm profile image
Starahelm in reply to trevg

Thanks for that trevg. I've received a list of private doctors from Louise today. Not cheap by any measure, especially with a holiday being saved for, but needs must. If it's tricky to take, I'd rather pay out for a practitioner to assess me and start me off than just try to do it myself.

trevg profile image
trevg in reply to Starahelm

Also- if you get private blood tests,outside done RT3 alone is around £70+ blood draw.

This should be lost in your overall charges, at least not as excessive.

Hopefully you will get Cortisol checked too, as that affects any thyroid course, but with T3 less so, I think due to not needing conversion.

I never have big issues taking it anyway, but did take good care.

NHS consultant has tried to get RT3 test,as it was on the lab list but, so far, I've had to get it myself. I think it's useful for me to know.

Wow. I just don't understand why the NHS in the UK behaves the way they do, especially when it's causing unnecessary suffering to people they could easily help.

trevg profile image
trevg in reply to Starahelm

Partly cost due to inflated charges from Pharma.

Other thing is , as you'll see on here, is that T4 has been hyped for so long by the BTA /RCP, in a nice lock down.

No NHS Endo wants to ruin a career taking the case to them.

[REF: DR.Gordon Skinner, late GP]

The only main doubt long term is the risk of osteoporesis increasing on T3. There's not much research, but some doubt from at least one supporter of using T3 - enough to advise caution.

On taking it, it may cause palps, oedema ot higher BP -which is why it needs watching.

I'm fairly fit for my age and can take it OK, even though technically elderly.

I still dance tango for 3 hours and walk 8 miles on the hills.Now my mojo is back!

If I'd been unfit and not persisted with my own tests etc I may not have got on it.

Definitely helps to have a kindly GP and the right consultant to go forward. Wilson'd is not believed in our NHS, as it takes them into bad territory Re T4 therapy -which will probably make it worse.

Having a nice wide 'range window' on TSH means you will be well on the way to expiring before they need to do much :/ sardonic.

I'm still waiting to see if the last RT3 test was completed.I did a private one after a T3 cycle and it was down 20% which seemed good enough to me. I go up to 50ugs T3 in stages and reduce over a couple of weeks to not stress my system. I feel my thyroid start to work again as tightness in the throat. It takes 20ug to shut of the bodys regulation so without T4 being taken recovery of endogenous T3 can be slow, I feel.

Nevertheless, reduction of RT3 is the goal - & not instant health [Haha] So, I determined to take it steady and not exceed 50ugs T3 where I feel FT3 >10 and TSH 0.01 risking the unknown as well as giving some side effects!

This reading if FT3 was on daily T3 so no way of knowing the median level that would mark the functional effects more cleanly.

Cessation of T3 & a delay in testing shows previous levels of FT4, FT3 and TSH recovering.

As little or no research is done in this specific area we seem to be on our own.

At least the internet gives courage to those who are prepared to fight their corner in the NHS- but it's a long haul.

How much was that big dose btw & how long actually on it ? TIA

I had the same effect on T3 only. After clearing reverse T3 (not a pleasant experience), I could only tolerate a small dose of T3.

I was rather glad to be honest. The really high dose of T3 I needed to function while I had high reverse T3 was unaffordable in the long term. But I can afford the small dose I take now. (I'm currently taking a mixture of NDT and T3 - but mostly NDT.)

Not sure I could do that for long. I got to 60 but getting tremors and feeling a bit under.

On ceasing it my sinus clears and I feel more normal after a week or two with reduced mojo as well. Due to age [70+] I have to be circumspect but at least I don't have to pay for T3.

T3 actually increases risk of Osteoporesis according to at least one peoponent-but the research is thin.

It also increases SHBG and ties up androgens so not a cureall.

Getting RT3 down is a mission, all the same.

You need supporting nutrients to ensure correct conversion of T4. This what makes the use of Levo as a one stop solution faulty.

You also need to correct any illness or stress that is making you track that way

Selenium, Zinc and many more supps are needed, let alone Iodine, which has to overcome all the resident Halides from Fluoride, Chloride that block cells -as does RT3.

Huge amounts of dietary knowlege are missing from Drs and Pharma ,as we know, like it this way.

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