Thyroid UK
84,129 members99,107 posts

Blood test results after 4 weeks of stopping levothyroxine

Hi everyone,

You may have seen my last post where I told you of the situation where Dr T instructed me to withdraw from levothyroxine for 4 weeks and get my bloods tested. The main reason for this is because my TsH remained normal when I was diagnosed 2 years ago, despite brutally low free thyroid hormone levels.

3 weeks into withdrawing from levothyroxine I experienced a return in my symptoms including crippling tiredness.

Here are the results of my bloods:

T4 - 7.9 (7.9-20)

T3 - 4.8 (3.8-6)

TSH- 4.25 (0.34-6)

Other bloods I requested

Ferritin 28 (11-370)

B12- 525 (120-625)

Folate - 15.9 (<3 suggests deficiency)

Vit D - 56 (<50 suggests deficiency)

So clearly my TSH has responded and come up very quickly from it being previously suppressed at 0.07 all the time or thereabouts. My t4 was previously always in the top of the range and now is basically at the bottom. T3 is somewhat normal. However this was only after 4 weeks and presumably I would still have had Levo in my system. I'm sure after another 2-3 weeks my TSH would continue to rise and free thyroid hormones continue to fall. Is it safe to say I definitely am under active and do you think Dr Toft will agree and that I should be taking meds? I am not seeing him until 23rd December but he did instruct me to take my meds between this blood test and then.

I am concerned about my ferritin as it is very low (although not low enough to be under normal range) although seen people on here advocating for a level above 70. What is the best way I can get my ferritin levels up? Presumably this is also contributing to my tiredness. I don't eat meat or fish so can't really get it from red meat etc. I'm more thinking on the lines of a good supplement if anyone has any recommendations.

Looking forward to reading your responses- I swear this forum keeps me alive and sane !!

11 Replies

It does look like hypothroidism but perhaps due to minor pituitary underactivity. You will still have the benefit of about 10 levothyroxine left in your system after four weeks (from 150 mcg). I would be inclined to resume at 100 mcg levothyroxine as you said you were over-active on 150 mcg. This would perhaps give Dr Toft more meaningful numbers on the next blood test (assuming one will be done) and allow him to give his opinion.


I would assume as well, that the reason my T3 is higher is because some of the loss of unreplaced T4 has been converted to T3 so that will be the last thing to be affected?


MK366, ThyCa patients are taken off Levothyroxine 4 weeks before RAI to enable TSH to rise >30 and uptake the iodine. There may be traces of Levothyroxine in your system but it's not enough to be helpful evidenced by TSH rising and FT4 dropping which show you are hypothyroid and require replacement. FT3 may be as good as it is due to high-ishTSH stimulating conversion which will also have 'used up' available T4.

Feritin is optimal >100 through to half way through range. Supplement iron with 500-1,000mg vitamin C to aid absorption and minimise constipation.

VitD is replete 75-200, and most people are comfortable around 100. Supplement 5,000iu D3 daily and retest in April.

Levothyroxine should be taken 4 hours away from iron and vitD.

B12 525 is adequate but 1,000 is optimal. B12 is only available from meat, fish and eggs so vegetarians should supplement methylycobalamin to compensate for dietary lack. 1,000mcg daily will be sufficient. Take a B Complex vitamin to maintain folate and keep the other B vits balanced.


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.


Thank you very much Clutter, as always :D

Do you have any recommendations for ferritin ? i've trawled the threads but just don't really know which one is good as a starting place.


MK366, Ferrous Fumarate 210mg has good iron content.


Well, Dr T's test worked a treat in that you are hypothyroid. A TSH of around 3 will be diagnosed as hypo in many countries except the UK, so that shows for sure how important clinical symptoms are and should take place above a TSH which sometimes never rises to 10 - the number the BTA have settled upon.

Others will recommend how to raise your ferritin and you will also feel better too.



haha, yep! thanks Dr T! well worth the $$$

I also asked my GP if I should go back on a starter dose of 50mcg. I actually felt best at 75mcg and it has been at doses above that where I have felt more unstable and up and down since. She was like NO DO WHAT THE SPECIALIST SAYS AND TAKE 100MCG.

but I guess I could just do alternate days or something to slowly build up and find that nice point where my TSH is low but not suppressed and my free hormones are mid- top of range. This is the situation when I had 75mcg and when I felt best.


Some feel best wish a suppressed TSH. Dr Toft also says so in his Pulse article:-

6 What is the correct dose of thyroxine and is there any rationale for adding in tri-iodothyronine?

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).

Even while taking the slightly higher dose of levothyroxine a handful of patients continue to complain that a sense of wellbeing has not been restored. A trial of levothyroxine and tri-iodothyronine is not unreasonable. The dose of levothyroxine should be reduced by 50µg daily and tri iodothyronine in a dose of 10µg (half a tablet) daily added.

While taking both hormones it is important serum TSH is normal and not suppressed."


That makes sense. I think I achieve complete suppression on 100mcg, I might just resume back on that, as he has suggested, and get my bloods done in 6 weeks to see where all of my hormones are at.

Thank you


if those aren't free's, than they tell even less about things. Total is very much not used these least were i am. Never had a total t4 and t3, by 5 endo's i have been too.


They are frees :)


You may also like...