GP reduced my levothyroxine dose: I've been on... - Thyroid UK

Thyroid UK

120,368 members140,113 posts

GP reduced my levothyroxine dose

GraceB profile image

I've been on 100mcg T4 and 31.25mcg T3 for almost a year now and feel myself again.

However, after last blood test, my endo concluded that I'm overmedicated and recommended to reduce my T4 dose to 75mcg.

The results were TSH < 0.01, fT4 15, fT3 8.9 - I know there are no ranges and these results are useless but this is as I've got it in the letter from my endo. I've put the enquiry to get complete results but this can take ages.

Anyway, the main argument is that my TSH is suppressed and this is dangerous for my health so my GP immediately reduced the T4 dose on my repeat prescription.

I'm still taking 100mcg T4 as have stock for another month. GP prescribed a new blood test but this surely shows my TSH suppressed. I tried to explain that I'm taking T4 and T3 so my TSH will be suppressed because it's how it works.

I just was wondering if anybody was in a similar situation when GP decided to reduce the medication dose? I would appreciate any advice on how to deal with it. Thank you :)

12 Replies

Your T3 looks like it's possibly to high, depending on range of course but it's not good to have it over the top. Low TSH not such a problem.

GraceB profile image
GraceB in reply to bantam12

Thanks bantam12 :)

shaws profile image

First of all - do you have your blood test at the earliest possible time? Fasting (you can drink water)? and allow a 24 hour gap between your last dose and the test and take afterwards.

This procedure allows our TSH to be at its highest in order to avoid all these stupid adjustments to 'fit' the TSH into a range.

These Endocrinologists and doctors have no absolute certainty that a low TSH means we will become hyperthyroid or put or health in danger.

If someone has had cancer of the thyroid gland, they must have a very low or suppressed TSH but they don't drop dead with heart attacks etc.

They ruin people's health by adjusting dose up/down according to the TSH. Tell GP you do not want a reduction as it is making you unwell and you want to go back to your dose. Tell him you don't want to be forced into sourcing your own.

Some links which will help you:-

The Professionals need to be trained and most on this forum know far more than those who are 'supposed to know'.

The blood tests were introduced for levothyroxine alone. Therefore if we add in T3 or NDT the numbers cannot possibly relate. The following doctor, and Adviser to Thyroiduk before his death only took a blood test for the inititial diagnosis and thereafter it was all about relieving the clinical symptoms by increasing every 2 weeks by a small dose (NDT or T3) he would never prescribe levo.

GraceB profile image
GraceB in reply to shaws

Many thanks shaws :)

shaws profile image
shawsAdministrator in reply to GraceB

This is the link with other topics at the top of the page. Some may not work as it is archived due to Dr. Lowe's death:

GraceB profile image
GraceB in reply to shaws

I've just realised the blood test was around midday. I was fasting but it was no longer than 6 hours after tablets.

Thanks for highlighting the correct routine before the blood test.

shaws profile image
shawsAdministrator in reply to GraceB

It does make a difference. Just phone your GP and ask for another blood test. He probably doesn't know early a.m. or after food can give different results.

SlowDragon profile image
SlowDragonAdministrator in reply to GraceB

Say you were taking biotin and hadn't realised that this can falsely affect test results and ask for repeat testing

All thyroid tests should ideally be done as early as possible in morning and fasting.

When on Levothyroxine, don't take in the 24 hours prior to test, delay and take straight after test. If also on T3, make sure to take last dose 12 hours prior to test.

This gives highest TSH, lowest FT4 and most consistent results. (Patient to patient tip, GP will be unaware)

GraceB profile image
GraceB in reply to SlowDragon

Thank you SlowDragon.

That's very helpful :)

SeasideSusie profile image


When did you take our last dose of T3 prior to the blood test? It should be between 8-12 hours. Last dose of Levo should be 24 hours.

Your results could reflect one of two things

1) You may be slightly overmedicated with T3

2) You took your last dose of T3 fairly close to the blood draw

The TSH is irrelevant, you are taking T3 and as you know that will often suppress TSH, your doctor should know this if he is prescribing it.

Your FT4 shows no need for your Levo to be reduced if it is within range, which I expect it is because taking T3 tends to reduce FT4. My lab's range is one of the lowest at 7-17 and you would still be well within range if your lab's range is the same. We more often see FT4 range of 9-19 or 12-22 on here.

GraceB profile image
GraceB in reply to SeasideSusie

Thanks SeasideSususie. The blood test was 4-6 hours after medication. This possibly explains higher T3. I'm having another test end of this week and will do it properly this time. Many thanks again :)

SeasideSusie profile image
SeasideSusieAdministrator in reply to GraceB


Yes, you could have a false high due to taking your T3 too close to blood draw. It will be interesting to see what your new test result is.

You may also like...