Why has supplementing with T3 caused levels to go DOWN?!

[Confused22]

Hello All,

Hope someone can help. I have been on 75mcg of T4 and 10mcg of T3 for the last three months. For the last 6/7 weeks I have felt really rotten – weight gain, depressed, needing an almost daily afternoon nap, brain fog, aching joints, etc. I had a blood test this week and just got the results and now I know why! Since I was diagnosed with Hashimotos and started thyroid testing these are the worst my levels (except TSH) have EVER been. Can anyone shed any light on why? Why would my T3 plummet when I’m supplementing with 10mcg per day (in 2x5mcg split doses)?! I have an appointment with an Endocrinologist to discuss next week but want to go in prepared with any suggestions or questions you can all think of:

TSH: 0.9 {0.27-4.2}

T3 4.2 {3.1-6.8}

T4 11 {11-22}

Previous results (14/03/22) on just 100mcg T4: TSH 0.9, T4 18.

T3 last tested Nov 2021 and was 4.5 on 75mcg T4

I am on a gluten, dairy, egg and soy free diet. I supplement with Iron, Vitamin C, Vitamin D, Calcium and Folic acid, but all away from my thyroid meds. I try to have 3 brazil nuts per day for selenium. Tests are always taken in the morning, after a 12 hour fast and 24 hours after levothyroxine (And this last one 12 hours after last T3 dose). Vitamin D was 79 [greater than 51] in December and Ferritin was 56 [30-150] when tested in Feb this year.

Any advice and suggestions will be gratefully received. I feel like it keeps being one step forwards and two steps back, all the while my life is passing me by. Thank you all in advance

[SeasideSusie Remembering]

Confused22

Since I was diagnosed with Hashimotos

I think this is your answer. You have Hashi's and typical Hashi's activity is for levels to fluctuate, you can go from stable to a hypo episode and swing to a "false hyper" episode where results show low TSH with high FT4/FT3. Temporary adjustment to dose of thyroid meds might be necessary during these episodes.

[Confused22 in reply to SeasideSusie]

Thanks for replying SeasideSusie. How is best to manage this situation/condition? If endo prescribes x amount of T3 and T4, how can I take more or less as I feel my body needs without my prescription running out too soon? And having to wait 3 months after every dosage change means I’m feeling like this for weeks before it can be considered. Is it just the lot of a hashi patient and something I just have to live with?

[SeasideSusie Remembering in reply to Confused22]

Confused22

I don't have Hashi's so no personal experience to pass on I'm afraid.

All I know is that you wouldn't ask your endo to lower your dose if you were going through a "hyper" episode, if prescription is lowered you may never get it back up again, so you'd adjust dose yourself without any change to your prescription.

All I can suggest is make a new post with a title that attracts the attention of members with Hashi's and ask how they manage.

[Confused22 in reply to SeasideSusie]

Thanks SeasideSusie, that’s good advice, thank you

[tattybogle]

So they reduced your levo from 100mcg to 75mcg when you started T3 3 months ago?

~ and your fT4 has now fallen from 18 to 11[12-22].

~ and you've felt lousy for the last 6 weeks.

~ and it would take about 6 weeks for you to feel the full effect of that reduction in levo dose ......

Seems to me like its your fT4 that has plummeted.

And that would be because they lowered the levo .. which will obviously lower your ft4 .... (and adding T3 often tends to lower T4 a bit too.)

Just looks to me like they reduced your levo dose more than was necessary when they added T3 , so presumably he next logical step would be to ask to increase the levo a bit and leave the T3 dose where it is for now.

eg add an extra ....12 .5mcg or 25mcg Levo .. and then see how that feels after a couple of months , and get retested .

Endo will no doubt be very please with themselves because they've managed to add T3 and keep TSH still in range at 0.9 Hurrah !..... but they've only managed to keep your TSH in range at the expense of lowering your fT4 so much it's now crawling along the very bottom of the range and you feel rubbish . .... so sod the TSH ... ask Endo to pay attention to the fT4 an FT3 levels and your symptoms first .....

the TSH being in range should come second.

anyway ...It's still along way from being 'supressed' at 0.9

0.01 or <0.01 is 'supressed'.

A very large /long term study of people on levo showed that TSH that was 'low but not supressed' (0.04 to 0.4 ) was NOT associated with any greater risks for heart /bones than TSH in range. academic.oup.com/jcem/artic... .

obviously once using T3 ,then TSH may go lower than it would on levo alone , so for some people using T3 this paper isn't much use as evidence ... but since yours is still 0.9 this paper could still possibly be useful to persuade endo to increase your Levo dose back up a bit .

For links to other useful posts and discussions about Low TSH / Risks/ Quality of life ..please see my reply to this post (3rd reply down) healthunlocked.com/thyroidu...

[Confused22 in reply to tattybogle]

Thank you tattybogle for your very thorough response to my question, I really appreciate it and the links were very helpful, thank you.

What you’ve said absolutely makes sense re the time frames for the T4. I think the solution here is to increase it again. I shall be ok the alert for the endo commenting on the tsh now too!

Can I ask - why would the T3 I’m taking not fill the gap? A 25mcg drop doesn’t seem a huge amount to make the levels drop so very much, especially when instead supplementing with 10mcg of T3 itself. Is it just a case of bad timing coinciding with a hashi flare as SeasideSusie suggests? Or is there something else I'm missing?

[tattybogle in reply to Confused22]

don't know ... but that 'old' fT3 result you are comparing the current fT3 result to, is from a relatively long while ago , you've been on 100mcg levo for a bit since then, and then changed again to 75 +10 T3 . lots of things could have changed in that time ... and even with no changes , we just get illogical results sometimes. ~ i've had experiences where i reduced my levo and fT4 has gone up...and increased Levo and fT4 went down..... go figure ?)

There are so many variables in the system for (deiodinase) conversion from T4 to T3, and (thyroidal) production of ready made T3 ... and by increasing your T4, then lowering it and adding T3, you have basically 'fiddled with quite a few of the knobs' on that system ..... so there are plenty of potential causes for seemingly illogical changes in T3 levels , even before you consider the possibility of a hashimoto's swing .

just because you got 'that much' fT3 last time you were on 75mcg , it doesn't follow that you'll get 'that much' T3 from it now.

and we don't actually know how much fT3 you were getting when you were on 100mcg levo do we ? you might have actually had less than you did on 75mcg.

there is no way of knowing what really happened ..... but in 'thyroid land' thing's don't stay the same , things aren't meat and tidy and predictable ,and things don't always add up ... one time you do 2+2 . you get 4 . then you do 2+ 3 for a few moths and get 5 , and you think you understand how it works ,,,then you go back to 2+2 and this time you get 7.... it's just the way it is . ... ( but it keeps life interesting eh :)_

i've got brain fade now and my eyes are going funny .. so if that reply makes no sense at all .. you'll have to let me off

[Confused22 in reply to tattybogle]

Thank you and no need to apologise, it all made absolute sense! Thank you for such a detailed explanation, put that way it does make sense why an increase of meds might see a ‘decrease’ in numbers, but in reality we’re not comparing apples with apples and the analogy of fiddling with a few knobs does indeed make sense.

‘Keeping life interesting’ is definitely a more positive phrase and way of looking at it all than the words I was using when I first saw my results 🤣. The management of this condition is so difficult. Or maybe not even possible with so many variables going on? We just need to fight each fire as it comes and accept things will never be level or normal for a prolonged period again.

Thank you again for your replies and explanations, I don’t feel quite so lost and frustrated with it all now, thank you