My recent blood test results from 10th July 2023, are as follow:
TSH- 0.31 mu/l (normal range 0.38-5.33)
Free T4 - 15.7 pmol/L ( normal range not known)
Free T3 - 3.8 pmol/L (normal range 4.0- 6.6)
Based on these results the GP has told me to reduce my present dose of Levothyroxine 100mg daily to 75mg for 3 days and 100 mg for 4 days.
From my very limited understanding of this complex condition, I believe that the TSH reading of 0.31 is well within the recommended range for a patient taking Levothyroxine. I am concerned about the low level of T3.
Is reducing the dose of Levothyroxine, as the GP recommends, the right course of action?
Any help would be so welcome. Thank you.
Written by
1Georgina1
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Your GP, like most, is using TSH as a guide to dose adjustment. Your TSH is below range so he is seeing that as you being overmedicated and suggesting that you reduce your Levo in an attempt to bring your TSH back into range.
Without knowing the range for FT4 it's not easy to argue your case. We can see that your FT3 is below range (and that is a narrow range for FT3, mostly it' something like 3.5-6.5 or 3.1-6.8) and that suggests that your FT4 might possibly be low in range or it just might suggest that your conversion of T4 to T3 is low. I would suggest that you somehow manage to get the range for FT4, especially as you have the other ranges it seems strange that you don't have that one. Have you had a print out from your surgery or can you see your results online?
I receive the results on line. I have written down exactly how they are presented. I will try to get the FT4 range but I think that it will be unlikely. Would increasing the Levothyroxine (counter to GP’s advice) improve the FT3 level. I have major symptom of tiredness and hair loss. Thank you.
Would increasing the Levothyroxine (counter to GP’s advice) improve the FT3 level.
Impossible to say but unlikely. Your FT4 might already be near the top of the range so you wouldn't want it any higher. Your below range FT3 will likely be the cause of your symptoms. So it's important to know the FT4 range so that we can then look again at all your results to get a full picture and maybe suggest a way forward for you.
..... but many GP's think anything under the ref range even slightly automatically means 'overmedicated' and will want to reduce dose , regardless of what the fT4 / fT3 levels are.
So they may have suggested you reduce dose based just on the below range TSH result ( and it's possible fT4 is also over range )
Main questions are:
do you feel well currently ?
what time of day was blood test done?
How many hours before test was last dose levo taken ?
ask GP receptionist for the ref range for that fT4 test .
Yes the below range fT3 is not great , (unless you feel well) .... most GP's won't be interested in fT3 level.... but some might agree to refer you to endocrinologist with a view to getting a trial of combination therapy (Levo plus some T3).. however not all NHS areas currently prescribe T3 to 'new' patients... bit of a postcode lottery at the moment .
I will endeavour to establish the normal range for testing FT3 from the surgery but this may be a big ask! The blood test was taken at 10.00am with the last dose of Levothyroxine taken the night before. The main symptom is tiredness with hair loss and dryness of skin and hair.
Thank you so much for your amazing invaluable help.
I have obtained from my surgery the normal range that is used for testing fT4 and it does not seem to correspond to either of the ranges which have been mentioned here! I have been given the range as 7.9 - 20.00. My reading of fT4 is 15.7.
Although not at the upper end, would you feel that it is adequate? My fT3 reading is regularly in the lower end of the range. I am satisfied that the TSH at 0.15 mu/l is okay.
Would you suggest I continue with 100mg Levothyroxine and not reduce it to 75mg as the GP recommended. She wants another blood test done in 8 weeks. I feel that is unlikely that she would or could prescribe a combination of Levothyroxine and T3. I can always ask her.
In the meantime I continue to feel exhausted and my hair falls out.
Your advice is very gratefully received. Thank you.
Tagging SeasideSusie so she sees your update. and so she can give you the email address to get list of Endocrinologists from ThyroidUK .
There are lots of quite different fT4 ranges in use ... (different testing methods/ machines) ..so to compare fT4 results from different labs you need to work out the '% through range' calculator here : thyroid.dopiaza.org/
(is TSH 0.15 or 0.31 ?~ original post said 0.31 )
FT4: 15.7 (7.9 - 20) 64 %
TSH- 0.31 (0.38-5.33)
Free T3 - 3.8 (4.0- 6.6) below range
i would not agree to reduce dose, due to your fT3 being under range .
There is nothing wrong with having a very slightly below range TSH as long as fT4 and fT3 are not too high ... your fT4 is nowhere near the top of the range , and reducing Levo dose is likely to reduce fT3 even further .
GP's may not agree about slightly low TSH being ok , but it really is 'only a little bit' under range ,it's no where near 'supressed' , so they shouldn't be too hard to persuade to leave dose at 100mcg , (especially since fT4 is very comfortable within range and fT3 is below range) ..... and for the sake of argument , if you'd happened to do the TSH test earlier at 8.30/ 9am , TSH might have even scraped into range. ( it's highest very early a.m then falls until it's lowest around 1-3pm)
A dose increase to 112.5mcg or 125 mcg may help you feel better , but it will be a struggle to get any GP to agree to prescribe it, due to current TSH level .
NHS GP's can't themselves prescribe trials of T3 /Levo combination therapy .... it must be initiated by an NHS endocrinologist ..... but it IS WORTH asking GP to refer you to endocrinology due to your BELOW RANGE fT3 result.
Use the low fT3 as leverage when GP wants to reduce dose ... say you want to stay on 100mcg until you have discussed your below range fT3 with an Endo .
Do your research first before asking GP for referral to Endocrinology dept .... see if there are any endo's in your area who are known to prescribe T3 .. (ThyroidUK has list of ones who have been known to prescribe it) ... no point getting referred to one who is fundamentally opposed to it's use.
Thank you so much. I understand your logic. I will remain on 100mg, for the next 8 weeks and see what the results are like then. If the fT3 remains stubbornly low, I will then make an appointment to see the GP to discuss the results with her. I will ensure I do my ‘homework’ before hand! It is enough to have to fathom the complexities of the condition without being up against it with GP’s whose understanding of the blood test results is highly questionable. I am so grateful to all the help and advice which I have received on this platform. It is truly a remarkable service. Thank you.
I have obtained from my surgery the normal range that is used for testing fT4 and it does not seem to correspond to either of the ranges which have been mentioned here! I have been given the range as 7.9 - 20.00. My reading of fT4 is 15.7.
Do you have an actual print out of your results which shows this range, or have you been given it verbally by one of the surgery staff?
It is a strange range and I'm not sure it's right. Most ranges we see here for FT4 have an interval of about 10, eg
7-17
9-19
12-22
It's always best to ask the receptionist for a print out, it's the only way to know for sure.
If it is correct then I agree with Tattybogle.
To obtain the list of thyroid friendly endos you can email ThyroidUK at
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