Low T3 from Private testing, what do my results... - Thyroid UK

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Low T3 from Private testing, what do my results mean and what can I do?

CeeKitty profile image

Hi, I'm new and I hope I'm doing this right. I'd like some advice/info and can't easily find it elsewhere due to concentration problems and fatigue.

As quick as possible overview. I am 41 and have been treated with levothyroxine for about 3 years now with absolutely no improvement in symptoms. I have a long term diagnosis of M.E.( Chronic fatigue syndrome) which I've had for 15+ years so it was hard even to get doctor to test thyroid because they blame everything on M.E. or my depression which I've had for 25 years.

I saw a endocrinologist 6 months ago because I had high cortisol and GP suspected Cushings. Endo thinks cortisol levels were from me being on the pill and wanted me to come off for a retest which has been done and an MRI to check for tumour on gland. She did note that my thyroid levels weren't optimal so recommeneded an increase from 100 to 125mcg levo. I've been yo yo-ing between 100 and 125 since I started treatment as they reduce it as soon as t4 reaches upper end of normal then it goes right down and so on. GP sent me for blood test to monitora couple of week ago and I've been told to reduce to 100 again. I've recently had some private thyroid tests including free T3. My TSH is low: 0.024 mIU/L (Range: 0.27 - 4.2) and T4 is high: 29.800 pmol/L (Range: 12 - 22) so it makes sense they're reducing dose but my T3 is low 2.84 pmol/L (Range: 3.1 - 6.8) .

OK, now the questions. Is this indicating that I am not converting T4 to T3? If so how can I get something done about it? I know the situation with prescribing of T3. What's the best way to bring this up with endo? My M.E. tends to have them seeing me as a hypochondriac who wants a magic pill but I just want to be as well as possible!

Hope this is ok I'm trying to gather as much info before appointment on Monday but I'm rather unwell at the moment.

thanks in advance

11 Replies
SeasideSusie profile image

Hi CeeKitty, welcome to the forum.

A couple of questions first.

Did you do all your thyroid tests under the same conditions so that they can be compared accurately? Time of day the test is done can make a difference, as can when you took your last dose of Levo, drinking coffee, eating, etc.

When doing thyroid tests, we advise:

* Book the first appointment of the morning, or with private tests at home no later than 9am. This is because TSH is highest early morning and lowers throughout the day. If we are looking for a diagnosis of hypothyroidism, or looking for an increase in dose or to avoid a reduction then we need TSH to be as high as possible.

* Fast overnight - have your evening meal/supper as normal the night before but delay breakfast on the day of the test and drink water only until after the blood draw. Eating may lower TSH, caffeine containing drinks affect TSH.

* If taking thyroid hormone replacement, last dose of Levo should be 24 hours before blood draw, if taking NDT or T3 then last dose should be 8-12 hours before blood draw. Adjust timing the day before if necessary. This avoids measuring hormone levels at their peak after ingestion of hormone replacement. Take your thyroid meds after the blood draw. Taking your dose too close to the blood draw will give false high results, leaving any longer gap will give false low results.

* If you take Biotin or a B Complex containing Biotin (B7), leave this off for 7 days before any blood test. This is because if Biotin is used in the testing procedure it will give false results (Medichecks definitely use Biotin, they have confirmed this and the amount of time to leave the supplement off).

These are patient to patient tips which we don't discuss with doctors or phlebotomists.

When you had your private tests done, was it just TSH, FT4 and FT3? Did you have thyroid antibodies tested? Vitamins - Vit D, B12, folate, ferritin?

OK, now the questions. Is this indicating that I am not converting T4 to T3?

It does look very much like you have a problem, but for good conversion to take place we need optimal nutrient levels, which is why we always advise having them done and addressing any low levels or deficiencies. Nutrient levels need to be optimal before considering adding T3.

If you haven't had nutrient levels tested, this is something you can ask your endo to do when you see him on Monday.

Hmm, that's an overwhelming amount of information and I wish I'd known all that before I had the tests done because it looks like I've wasted energy and money on results that aren't usable or really accurate.

I have had other tests but not in this last batch. Last GP tests several months ago showed vitamins all "normal/good" I don't have the values. I take b12 and VitD. I showed thyroid antibodies when GP started treatment.

Not really sure where this will lead with the endo. She actually said last appointment that if I don't have cushings I'll he discharged back to GP with advice to keep my thyroid levels optimal but they'll only be monitoring tsh. I doubt she will respond well to me asking for other tests on her budget. I can't afford to keep having private tests, I'm so unwell I cannot work.

Thanks for information

SeasideSusie profile image
SeasideSusieAdministrator in reply to CeeKitty

Last GP tests several months ago showed vitamins all "normal/good" I don't have the values.

Normal/good doesn't tell us much, we need optimal for thyroid hormone to work properly so we need to see the actual numbers.

You can ask at your surgery's reception desk for a print out of your results. In the UK we are legally entitled to our results without charge, just ask the receptionist. Don't accept verbal or hand written results, mistakes can be made, get a print out and do this for every test you have, keep a record, it will become invaluable in the future.

I take b12 and VitD.

How much do you take? Are you monitoring your levels?

It's important to test Vit D twice a year when supplementing to keep within the range recommended by the Vit D Council/Vit D Society which is 100-150nmol/L. Excess Vit D gets stored and can lead to toxicity levels.

When taking B12 we need a good B Complex to balance all the B vitamins. If B12 isn't too low, a good B Complex is all that is needed as the methylcobalamin (B12) it contains should be enough. Good brands are Thorne Basic B or Igennus Super B.

B Complex usually contains Biotin and as mentioned above this needs to be left off for 7 days before any blood tests as biotin is often used in the testing procedure and gives false results.

I showed thyroid antibodies when GP started treatment.

Raised antibodies suggest autoimmune thyroid disease, aka Hashimoto's, which is where the immune system attacks the thyroid and gradually destroys it. Hashi's can cause fluctuations in symptoms and test results as you can swing from hypo to hyper and back. This could very well be the reason for the swings in your hormone levels and the reason for the adjustments in your dose of Levo.

Your recent results of TSH: 0.024 mIU/L (Range: 0.27 - 4.2) and FT4: 29.800 pmol/L (Range: 12 - 22) could be a hyper swing.

Most doctors dismiss antibodies as being of no importance and know little or nothing about Hashi's and how it affects the patient, test results and symptoms. You need to read, learn, understand and help yourself where Hashi's is concerned.

Some members have found that adopting a strict gluten free diet can help, although there is no guarantee.

Gluten contains gliadin (a protein) which is thought to trigger autoimmune attacks so eliminating gluten can help reduce these attacks.

You don't need to be gluten sensitive or have Coeliac disease for a gluten free diet to help.

Gluten/thyroid connection: chriskresser.com/the-gluten...





Supplementing with selenium l-selenomethionine 200mcg daily can also help reduce the antibodies, as can keeping TSH suppressed.

Hashi's and gut absorption problems tend to go hand in hand and can very often result in low nutrient levels or deficiencies so it's important to test these.

I appreciate that Normal/good doesn't tell you much but I've not been to the surgery to get a copy of the results yet as I only had a phone consultation to discuss them. I don't monitor myself as I can't afford it, GP sends me for tests to monitor. This is the first time my t4 has been high outside of normal range, he usually changes dose to keep me in the lower end of normal.

I don't eat gluten and I've been reading up on best diets for my conditions. I barely eat anything to be honest because I'm constantly gaining weight. I've tried to educate myself but I'm too ill, I either don't understand or don't remember it. Long before I had thyroid problems I was too ill for that much brain work.

To be honest I feel incredibly deflated. I thought I might be able to get some help from a doctor with T3 because I've been told many people's health turn around on that basis. It would seem that until such time as I can educate myself fully I'm stuck like this.

Thanks for your time and the information

SeasideSusie profile image
SeasideSusieAdministrator in reply to CeeKitty

This is the first time my t4 has been high outside of normal range, he usually changes dose to keep me in the lower end of normal.

Keeping your FT4 at the lower end of normal is wrong.

The aim of a treated hypo patient generally is for TSH to be 1 or below or wherever it needs to be for FT4 and FT3 to be in the upper part of their reference ranges, if that is where you feel well.

Dr Toft, past president of the British Thyroid Association and leading endocrinologist, states in Pulse Magazine (the magazine for doctors):

"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).*"

*He recently confirmed, during a public meeting, that this applies to Free T3 as well as Total T3.

You can obtain a copy of the article by emailing Dionne at


print it and highlight question 6 to show your doctor.

I barely eat anything to be honest because I'm constantly gaining weight.

Weight loss is difficult unless FT3 is at a good level, but barely eating anything wont be doing you any good at all.

T3 can only be initiated by an endo so you would need a referral to a thyroid friendly endo. Send for the list from Dionne at ThyroidUK


then you can ask on the forum for feedback by private message on any that you may be able to travel to, then ask your GP to refer you to one that seems hopeful of getting somewhere with. Endos can refuse referrals but the results you have given in your opening post with FT3 below range may mean that you will be seen and possibly be considered for a trial.

Thank you, One last question. I will be taking a copy of my most recent GP blood tests to endo I'm seeing on Monday. Is it worth showing her the private one with the T3 results. I'm not sure her attitudes be because thyroid wasn't the focus of my only previous appointment though she was concerned that last results weren't optimal.

I really do appreciate you taking the time to go through this with me

SlowDragon profile image
SlowDragonAdministrator in reply to CeeKitty

Absolutely take all blood test results along to endo

Point out very low FT3

Request that endo test vitamin D, folate, ferritin and B12

If taking any supplements with biotin in, stop these a week before consultation if you think you will have blood test then and there.

New NHS England Liothyronine (T3) guidelines July 2019 clearly state on page 13 that TSH should be between 0.4-1.5 when treated with just Levothyroxine

Note that it says test should be in morning BEFORE taking Levo thyroxine

Also to test vitamin D, folate, B12 and ferritin


TSH is often very unreliable with Hashimoto's

Canadian Thyroid association article on Low TSH


Most important results is FT3

Testing vitamins is first step

Levothyroxine should always be taken on empty stomach and then nothing apart from water for at least an hour after

Many people take Levothyroxine soon after waking, but it may be more convenient and more effective taken at bedtime

All medication at least two hours away from Levo. Some like HRT, PPI's, magnesium, iron or vitamin D, at least four hours away


Many people find Levothyroxine brands are not interchangeable.

Once you find a brand that suits you, best to make sure to only get that one at each prescription. Watch out for brand change when dose is increased or at repeat prescription.

Many patients do NOT get on well with Teva brand of Levothyroxine. Though it is the only one for lactose intolerant patients. Teva is the only brand that makes 75mcg tablet.

Hi SlowDragon,

Curious whether your comment about Teva being the only brand to make 75mcg tablets holds true in the US as well?

Thank you!

Hi, Sorry to read about all your troubles. Sounds like you may need to re run all tests to get best picture then try to get referred to T3 friendly Endo from Thyroid U.K. list? T3 hasn’t been the magic bullet for me - hard to take without feeling hyper and it’s not moved my T3 level. But - I’m of the school, like many on here, that you need to try everything (and slowly and carefully). If I can’t get a bit better with Endo help, I’ll self source NDT...

With your T3 being so low and T4 too high and your TSH very low basically saying reduce T4 and increase T3.

I would definitely push for T3 thyroid tests on the NHS. It looks like you are a very poor converter of T4 to T3. If this is the problem you can have a gene test done through Rengenerus Laboratories privately. Some people have a fault in a gene DIO2 which leads to a decreased ability to generate active T3. T3 is the only hormone our body uses as T4 is just sitting waiting to be converted. Without T3 or very low T3 you will remain with hypothyroidism symptoms. This gene default can also lead to obesity and poor physiological wellbeing.

I have been told over the years that I was suffering from depression but I knew I wasn’t as my life was fine. All along it’s been the lack of T3. I was diagnosed with Hashimotos 12 years ago and put on Levothyroxine. I was always having to lower the dose. Started at 125mcg now on 75mcg along with T3 medication. It wasn’t until this year,after 11 years of suffering which got worse over the years to a point of constant collapsing and hospitalisation and no Dr knowing what was happening to me, that I finally went private and got my T3 tested and had the DIO2 gene test done also which revealed I needed T3 medication all along. Since starting T3 in April this year it has given me my life back. I can’t believe still how Drs didn’t know or didn’t think to check my T3. I had no clue then. Only when finding this forum has a number of light bulbs come on.

If you want to see a private Endocrinologist just pm me and I will give you his details.

I did have low ferritin and low B12 which has now been addressed. Mainly as I am a vegetarian and not getting enough of the vitamins.

I would definitely take your results to your Drs appointment. However, the NHS is very poor at prescribing T3. I fought and fought for it in the NHS who kept telling me I don’t have an Endocrine issue, when I clearly did. I’ve now got T3 on the NHS but keep my private Endocrinologist as a back up.

Although timing wasnt perfect on your test, it's still valid when discussing this. And it looks very much like my results when on levo only. I also have a familial history of osteoporosis and so the conclusion was that I have a genetic DI02 mutation. I've never bothered to test it because it would make no difference to my treatment.

Before the T3 travesty really started I actually had two trials of liothyronine. Sadly I had a very severe reaction, with very severe rheumatic symptoms. That is very rare though. And at that point they pretty well washed their hands off me.

My solution was to self medicate with NDT. I'm lucky that my current GP wont prescribe, but he does test. If he didnt then I would do that. Yes it costs, but not much, and to be honest I'll go without most things to pay for my meds (currently £150 for 500 days treatment) because without I would top myself!

Before being diagnosed hypo I was also diagnosed with ME and fibromyalgia.

The only way I could lose weight was to eat keto. That also improved conversion and I had to reduce my NDT. Not eating will do long term damage to your metabolism, and makes little difference to the weight gain.

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