Thyroid UK
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Should T4 be higher to feel better?

Hi, I've been chipping away at the doctors over the last year and have been steadily increasing my levothyroxine from 25mcg to 100mcg. I feel okish now but still lots of symptoms, I don't know if I'm wanting too much but I want to feel as good as I can get.

I'm seeing the GP tomorrow but my latest blood test results are:

tsh 0.19 (0.27-4.2)

T4 16.17 (12-23)

I read in Dr Tofts book that some people only feel better with a tsh in the lower range which I have now and a T4 in the upper quarter of the range.

Am I expecting too much to have no symptoms on a daily basis? how would T4 increase when my tsh is so low??


7 Replies

Your results are very similar to mine; a low TSH but with T4 not particularly high and certainly not at the top of the range. There are many reasons for this. Your TSH might be artificially low, and therefore not very representative of your thyroid status because you have low cortisol or low B12 or perhaps both.

If you haven't already done so, I would recommend getting the following tests; serum iron, ferritin, vitamin B12, folate and vitamin D. All have symptoms similar to hypothyroidism and it is also believed that deficiencies in any of them can affect how efficiently your cells are able to use the thyroid hormones.

You may also benefit from a slightly higher dose of thyroxine but you may find that your doctor refuses.

If after your levels are optimal for the vitamins and minerals above (and well within range, nowhere near the bottom!), you are still feeling unwell, it may be that you need a thyroid replacement containing T3. This isn't something most doctors are happy to prescribe and I do believe that a lot of that is down to cost.

I would concentrate on getting the blood tests done and correcting any levels with supplements first. There is a very good page on the main Thyroid UK website about the role of supplements in thyroid disease

Of course, if you have any questions about what optimal levels are (as opposed to the NHS "normal" levels) please do ask. You can even post your results here and someone will be able to advise.

I hope that helps a little :)

Carolyn x


Thanks so much Carolyn, I did have the vitamin levels etc tested about 6 months back and I was told that everything was normal but I didn't obtain a copy of the results. I have been taking B12 tablets for the last few months as I've been vegetarian for years and thought the levels may be on the low (but normal) side.

I'll ask for a copy of the results. I'm beginning to doubt myself as I don't feel no where near as bad as I did a year ago but at the same time I still struggle on a daily basis.

After trying a few GPs at the surgery I do seem to have quite a good one who did let me increase from 75mcg to 100mcg in January. I doubt whether he'd let me increase further though.

Thanks again Carolyn, i hope you feel better soon :-) x


How much B12 are you taking? Some people recommend a maintenance dose of 1000mcg, in the form of methylcobalamin, daily for hypothyroid patients. If you think you might be deficient you will probably need more, at least for a while. I take 5000mcg a day at the moment and am noticing some improvement.

You might want to take folic acid as well if you think this might be low but make sure you are taking at least an equal amount of B12 and probably more if you are vegetarian.

It would be great if you could get your results. Your B12 needs to be above 500, not the 180 that the NHS seems to think is ok! Many people have noticeable symptoms when their B12 is below 350. Your folate should also be well within the range and nowhere near the bottom. Ferritin really needs to be 70-90 at the very least. Some people are fine at 70, others need more. As you are vegetarian, your ferritin is likely to be lower than us carnivores simply because iron is more easily absorbed from animal products.

I hope that helps.

Take care :)

Carolyn x


That's so helpful, thanks Carolyn, I'm taking a 1000mcg B12 supplement from Holland & Barratt - I thought I was taking loads but I obviously need to swat up on the vitamin side of things a little!

I'll ask for a copy of the test results and come back, thanks again for veing so helpful!

Dawn x


Also make sure the B12 is methylcobalamin rather than cyanocobalamin. The methyl form is much easier for you body to absorb and use. I use the Jarrow methyl B12 tablets. You can let them dissolve under your tongue (they taste quite nice) so you will absorb some through the sublingual membranes so less gets "lost" in your digestive system.


summer, try to get your results so you can keep track of any changes. Your T4 is rather low. Lately I read that any T4 that does not convert to T3 becomes reverse T3. Of course, without testing your fT3 and reverse T3, it's hard to tell what your needs are. If nothing else, you could at least try an increase in your T4 to see if it relieves some symptoms. In these early stages, the least they should do are the T4 and T3 tests in order to see how you are handling your T4 medication. Very maddening. Try to stand up for yourself.


Thanks Heloise, I do seemed to have found quite a good GP who doesn't instantly dismiss me. On each blood test form he asks for T4 and T3 but usually they only do tsh and T4 if the tsh is out of range. This time they did do the t4 which isn't a whole lot higher than before I was on thyroxine, I think it was 10 then.

I saw the GP yesterday and he said he doesn't understand why the T4 isn't higher. He pondered for a while and then said that he'd increase me by 25mcg for a trial. He then changed his mind as he found a swollen gland one side of my neck, it always comes out when I'm tired by yesterday it was quite large so he's given me a week of antibiotics and then I have to go back and take it from there. Disappointed I didn't get the increase straight away but at the same time at least I know he's listening,

Prior to this GP I saw 3 GPs who dismissed everything I said, it was one of them who said all the vitamin blood tests were ok. I've wrote the letter requesting the blood tests and handed it in so now I just have to wait a few days for the results. At the same time I've been looking at this site for details of private t3 testing so I'm going to do that too.

Thanks so much for your advice, I do feel like I've learnt a lot over the last year but was totally stumped as to why the t4 wasn't higher.



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