When taking T3 should FT4 levels still be in op... - Thyroid UK

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When taking T3 should FT4 levels still be in optimal range

Handsome14 profile image
18 Replies

I have hypothyroidism and I'm taking T3 and T4 medication. I know that taking T3 causes FT4 levels to decrease but should I still be aiming to have FT4 at an optimal level.

I can feel I need an increase (waiting for blood test results) but not sure if it's an increase in T3 or T4 that I need.

Any advice would be greatly appreciated. Thanks

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18 Replies
SeasideSusie profile image
SeasideSusieRemembering

Handsome14

should I still be aiming to have FT4 at an optimal level

Optimal is where you feel well so in that respect the answer too your question is yes. However, there is no number to aim for because we are all different and what's optimal for one person is not the same as optimal for someone else so in that respect there is no general "optimal" level to aim for, just aim for where you feel well.

When on combination thyroid hormone replacement we are very individual as to where we need our FT4 and FT3 levels to feel well and we find those levels by trial and error and gradual tweaking of doses of Levo and T3 until we find our sweet spot. Some people are fine with a low FT4 as long as FT3 is in the upper part of it's range, some need both FT4 and FT3 to be fairly well balanced usually over half way through range.

Post your new results when you have them, include the reference ranges because they vary from lab to lab, and as long as you have TSH, FT4 and FT3 results we will be able to comment. It's absolutely essential to include FT3 when taking combination thyroid hormone replacement.

Handsome14 profile image
Handsome14 in reply toSeasideSusie

Thanks for your prompt reply and advice. I'll post results as soon as I receive them

SlowDragon profile image
SlowDragonAdministrator

Looking at previous posts couldn’t see any recent vitamin results

What vitamin supplements are you currently taking

For full Thyroid evaluation you need TSH, FT4 and FT3 tested.

Very important to test vitamin D, folate, ferritin and B12 at least once year minimum

Recommended on here that all thyroid blood tests early morning, ideally before 9am last dose levothyroxine 24 hours before test

On T3 day before test split daily dose into 3 smaller doses, spread through the day at approx 8 hour intervals, taking last 1/3rd of daily dose 8-12 hours before test

Private tests are available as NHS currently rarely tests Ft3 or all relevant vitamins

List of private testing options and money off codes

thyroiduk.org/getting-a-dia...

Medichecks Thyroid plus antibodies and vitamins

medichecks.com/products/adv...

Blue Horizon Thyroid Premium Gold includes antibodies, cortisol and vitamins by DIY fingerprick test

bluehorizonbloodtests.co.uk...

If you can get GP to test vitamins and antibodies then cheapest option for just TSH, FT4 and FT3

£29 (via NHS private service ) and 10% off down to £26.10 if go on thyroid uk for code

thyroiduk.org/getting-a-dia...

monitormyhealth.org.uk/

As you have Hashimoto’s have you had coeliac blood test

Are you on strictly gluten free diet or tried it?

Handsome14 profile image
Handsome14 in reply toSlowDragon

So just had blood test results back and I'm very confused.So I do feel better (although still not back to my normal self - if I can remember what that is!)

Ft4 10.3 (10.8-25.5) on 75mcg levo

FT3 5 (3.1-6.8) on 30mcg liothyronine (20mcg am & 10mcg pm)

TSH <0.02

I have hashimotos but I'm not swinging from hypo to hyper but rather progressed from subclinical hypothyroidism to overt thyroid failure

So my question is how can I feel better when my FT3 is lower than my last 2 blood tests when I didn't feel well

My Endo has agreed to increase liothyronine to 40mcg (20mcg am & 20mcg pm) and keep levo at 75mcg (he did want to reduce levo with the increase in liothyronine but I pushed for him to leave it at 75mcg) but he's said that this is the highest dose of liothyronine he will prescribe because he's concerned that my TSH is suppressed. I did say that I'd read that TSH is suppressed when taking T3.

So I remain confused why I should feel better (although not yet back to normal) when FT3 is 5 and FT4 outside of range and I'm worried that after the increase if I don't feel back to normal where do I go from there.

Hoping someone can shed any light and looking forward to all your helpful comments

Thanks

SlowDragon profile image
SlowDragonAdministrator in reply toHandsome14

Ft4 10.3 (10.8-25.5) on 75mcg levo

FT3 5 (3.1-6.8) on 30mcg liothyronine (20mcg am & 10mcg pm)

TSH <0.02

Everyone is an individual…but many many people on levothyroxine plus T3 find they need BOTH Ft4 and Ft3 at least 50% through range

Personally I would be looking to INCREASE levothyroxine

Perhaps initially to 87.5mcg and retest in 6-8 weeks

You’re likely to need to increase again to 100mcg levothyroxine daily

You may need to reduce T3 a little if Ft3 goes too high

But …it’s trial and error what suits each person

You might be better with less levothyroxine and more T3

Handsome14 profile image
Handsome14 in reply toSlowDragon

Thanks very much for your prompt response - it's very much appreciated 🙏

Handsome14 profile image
Handsome14 in reply toSlowDragon

Just got some follow on questions if I may and not sure if I should start a new post or whether others will see this (I'm not au fait with this platform)So I still don't understand how I feel better when my FT3 percentage has gone down. Before my FT3 percentage was higher when I was presumably getting some T4 conversion to T3 as well as directly taking T3 meds but now I presume most if not all of my T3 is coming directly from the meds but nevertheless my percentage is less and I feel much improved. The numbers don't make sense to me. Can anyone help explain this please 🙏

SlowDragon profile image
SlowDragonAdministrator in reply toHandsome14

5 months ago

on 125mcg levothyroxine and 10mcg T3

TSH <0.02 (0.27-4.20),

ft4 22.4 (10.8-25.5),

ft3 5.7 (3.1-6.8).

Now

on 30mcg liothyronine (20mcg am & 10mcg pm)

Ft4 10.3 (10.8-25.5) on 75mcg levo

FT3 5 (3.1-6.8)

TSH <0.02

Reducing dose levothyroxine from 125mcg to 75mcg was likely too much of dose reduction in levothyroxine

Did you ever try 100mcg levothyroxine and 20mcg T3

That would have been the logical step after test results 5 months ago

Obviously need to also consider vitamin levels too

When were vitamin D, folate, ferritin and B12 last tested

Handsome14 profile image
Handsome14 in reply toSlowDragon

Thanks for replying. Yes I did try that dose. I'll aim to get all my results in order and do another post but I'm still confused coz the numbers don't make sense. How on earth can I feel an improvement when my results 5 months ago look better than they do now. I can only assume it's the increase in T3. No?

SlowDragon profile image
SlowDragonAdministrator in reply toHandsome14

Some people only feel better with many T3 and only a little levothyroxine..

Perhaps you are one of those

Handsome14 profile image
Handsome14 in reply toSlowDragon

Does the 5.7 FT3 not mean there was more T3 in my body than the 5 FT3 that there is now

Handsome14 profile image
Handsome14 in reply toSlowDragon

Hello SlowDragon, just looking at this post and it seems I made a mistake.

So 5 months ago when I was on 125mcg T4 (FT4 22.4) and 10mcg T3 (5.7) my Endo then changed my dose to 150mcg T4 and 5mcg T3. Then in Nov to 175mcg T4 and NO T3

I am aiming to put together a table of my results and doses and post soon

Thanks 🙏

SlowDragon profile image
SlowDragonAdministrator in reply toHandsome14

5 months ago when I was on 125mcg T4 (FT4 22.4) and 10mcg T3 (5.7)

125mcg levothyroxine and 10mcg T3

TSH <0.02 (0.27-4.20),

ft4 22.4 (10.8-25.5),

ft3 5.7 (3.1-6.8).

my Endo then changed my dose to 150mcg T4 and 5mcg T3.

Results on this dose?

Then in Nov to 175mcg T4 and NO T3

Results on this dose ?

How much levothyroxine and T3 are you currently taking

Handsome14 profile image
Handsome14 in reply toSlowDragon

Thanks for response SlowDragon - I will endeavour to put together a table to make sense of it all and post as soon as I can get my head round it all but huge thanks for helping me as always

Btw I still can't really get to grips with this platform - are there any tutorials and do you (most people) use a laptop or the like? I use my Android smartphone but can't navigate as well as others seem to ie seeing posts from way back and having name highlighted so it's a link - any tips on this front would be greatly appreciated 🙏

SlowDragon profile image
SlowDragonAdministrator in reply toHandsome14

I use an iPad

I think a phone is perhaps not so user friendly

tattybogle profile image
tattybogle in reply toHandsome14

I use a lap top , because i'm a luddite and i still have a 'dumb phone' from the 1980's... i would be useless too if i tried to find my way round on here with a smart phone .

To highlight a name ~ put @ immediately before you type the name .

~ when you have typed it, (or part off it) a drop down list of names will appear at the bottom of the reply.

~ click on the appropriate name .

~ and then it will go blue in your reply.... ( 'going blue' shows it will work as a link).

Handsome14 profile image
Handsome14 in reply totattybogle

Super helpful tattybogle - big thanks 🙏

Handsome14 profile image
Handsome14

So should I not look at reference ranges then and simply just go off how I feel ? Also am I right in thinking that this is in keeping with me progressing from subclinical to overt hypothyroidism where I have less thyroid functionality and also having the homozygous DIO2 polymorphism meaning I have poor conversion hence needing T3.

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