T4 supplementation

Hi I'm 43 on 225 mg of thytoxine daily. Still tired unable to lose weight my levels are within range so gp won't refer me for endocrine or test my t4 levels.

I currently am taking in around 2000 calories and train 3 times a week but no weight loss. I am around 19 stone and it's having an effect on my health.

I'm tired of being tired so have to take matters into my own hands. On research feel that this may be down to low t4 as my other levels are ok.

Please could anyone with experience of supplementing with t4 give me any advice. I haven't got my levels to hand but was tested around 1 month ago

Many thanks

19 Replies

rogerant Thyroxine is T4. Do you mean T3?

For members to suggest anything we need to see your test results with their reference ranges. Ideally:




Thyroid Peroxidase antibodies

Thyroglobulin antibodies

Vit D




Vitamins and minerals are very important, they need to be at optimal levels, not just 'in range', for thyroid hormone to be able to work.

For 225mcg Levo to not be working then besides low nutrient levels there could be poor absorption due to gut problems, other medication affecting absorption, poor conversion of T4 to T3. If you can post your results we can see what might be happening.

I know it's desperate but I have quite severe but problems. IBS and I think colitis. I am useless at this and just feel so dejected at the moment. I will go to my gp and see if I can get a copy

Thank you

Have you had coeliacs ruled out? Please bear in mind that the coeliacs blood test is proven to be unreliable and only endoscopy can properly rule this out. Even if endoscopy is negative, I was diagnosed with non-coeliac gluten sensitivity as was proven to be the cause of all my issues but this is hard diagnosis to get. Many of us on here have found great improvements in our health and stomach by going gluten free so definitely worth a try even if just to rule out by must be 100% gluten free and for at least three months. Most of us were also diagnosed with IBS for many years before.

If this doesn't work, you can try an elimination diet to see if any other foods are bothering your stomach or ask for referral to endocrinologist for further investigation.

I think it appears you might have problems absorbing so getting your iron/vit b12/vit D and folate tested is a must.

Hope you feel better soon.

you need the results as suggested above to know if you are metabolising ok !

what's your height , weight and age - 2000 may be too many for weight loss .

A diet rich id good fats ( oily fish and avocado's and seeds ) and plenty of fruit and veg but you need to aim for the right calorie intake for your body size - I can give you an indication of your BMR ( ideal calories for individuals ).,

also if your T3 is low - exercise will deplete further ( preventing wellness and weight loss ) I only found that out from here the other day !!!

Totally agree , from experience , if you are low on T3 , you can crash big time following exercise .

I am 6 foot and currently 120 kg so clinically obese lol. I have really big frame mind you so carry the weight well but still massively overweight. I have been using calorie counter and sometimes don't even got 2000 calories

Thanks all help appreciated

If anything you are already at a 'weight loss ' calories intake - Your BMR is around 2400- 2500 ( ie what you should be taking on before you gain or loose weight !) ... But without your THS T4 T3 result ( pref Vit d B12 Folate and ferritin ) its hard to know what's going on - if you havn't got enough T3 you wont metabolise anywhere near normal and exercise can only make that worse - try just afew long walks till you get new bloods.

Hi yeah I'm taking in around 1900 calories a day but so far no weight loss sadly. My doctor is going to give me my blood results tomorrow so I will post them as I genuinely have no idea.

Thank you for your help I'm grateful

Hi finally got my blood results so here goes

Creatininine 107umol

Serum tsh level 1.27mU/L

Serum free t4 levels 16.8 pmol/L

Sorry no vit d or ferrate

I have no idea what any of this means


Hi - make a new post with these results to get the best feedback - cant tell what they are doing with the lab ranges - in brackets next to the results - real shame there is no T3 as that's the one that counts at the end of the day - re post with lab ranges.

I have IBS if my levels are low , but kind of an improvement on the constipation. I also have Hiatus hernia which contributes to the gastro issues ,but they all have improved a hell of a lot as I went up in the dose of NDT.

It was only after starting with NDT that I had IBS and gastro issues as I was around half the dose I needed, it went as I moved up. On T4 only I was badly constipated despite the 'in range ' results.

Lots of useful U go in the Thyroid Uk site and things to do and more importantly things to be wary of.

Thanks for all the advice I do think that I am sensitive to gluten and am trying to cut this out of my diet. I have had endoscopy and blood test with negative results but I notice the difference if I have lot of gluten.

As to exercise depleting my t3 it is a very important part of my life so will have to persevere with it for my sense of well being.

I am trying to get copy of my last blood results from gp but so far he won't disclose it for what reason I am not sure. I am contemplating having them done privately but even if they are out of whack I know he won't refer me to specialist so why spend the money.

I really do appreciate all the advice thank you so much

If you are in the UK then your doctor cannot refuse to supply your results, you are legally entitled to them under the Data Protection Act 1998. You should ask at reception for a print out (make sure the reference ranges are included) and if they are not willing then remind them of your legal right to have them and say you're sure they wouldn't want to break the law.

See 'Accessing your medical records' on ThyroidUK's main website


If you want to do private testing then Blue Horizon Thyroid plus Eleven or Medichecks Thyroid Check Ultravit both cover everything I mentioned in my post above



Hi finally got my blood results so here goes

Creatininine 107umol

Serum tsh level 1.27mU/L

Serum free t4 levels 16.8 pmol/L

Sorry no vit d or ferrate

I have no idea what any of this means


What about the reference ranges? Particularly FT4. As reference ranges vary from lab to lab a number on it's own has no meaning, it's where in the range you fall that matters.

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

Your TSH is fairly close to that but we have no idea where your FT4 lies, and FT3 would complete the picture as we would be able to see whether you are converting T4 to T3 well enough.

Ferritin is important because thyroid hormone can't work unless it is a minimum of 70 and half way through it's range is recommended.

All vitamins and minerals need to be at optimal levels (not just in range) for us Hypos and low nutrients bring their own symptoms too.

Creatinine tells us how well our kidneys are working.

So your results don't tell us much. What you really need is a full thyroid profile plus vitamins and minerals as mentioned in my first reply above. The private fingerprick tests I linked to above will give the whole picture and once you have all those results you should have a clue as to why you are tired and can't lose weight. My guess is possibly low T3, especially as you are exercising so much. It has been explained by other members that exercise will deplete T3 and if your T3 is already low then exercising will mean that it will be even lower. T3 is very important, it is the active hormone converted from the pro hormone T4, and every cell in our body needs T3.

Ok I'll try to look if I can get the ranges sorry but I really am rubbish lol it's all. I will look into blur horizon now

I would want to know all hormone levels but the T3 is very important . Have you had a private test for T3 , as I don't think you'll get one on the NHS ?

You may also like...