Does T3 always suppress TSH?: So I have been on T... - Thyroid UK

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Does T3 always suppress TSH?

buddy99 profile image
24 Replies

So I have been on T3 for 3 weeks and my TSH plummeted from 1.79 to 0.04 (0.4 - 4). The FT4 stayed pretty well the same (at about 78% within the interval) and the FT3 did really not move significantly (to my thinking anyway). It moved from 3.7 to 4.1 (3.5 - 5.9). Obviously there is concern about the low TSH and I'm supposed to get off the T3 again (after fighting to give it a try for years on end). I'm on the lowest dose, 5mcg and tried to split that into 2 doses. The pill is very small, though, and very chalky. It can not be split without pulverizing it (definitely does not split in half). I don't really want to give up the T3 and would rather want to lower the T4. Any suggestions, wonderfully knowledgeable combatants, on how to move forward? Thank you! :)

I should add the D level was not measured but since I take 5000 daily it should not be low. B12, ferritin were all in the upper range (B12 even above range). Test was done 24 hours after taking both T3 and T4 the previous day at 8:30 am.

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24 Replies
SeasideSusie profile image
SeasideSusieRemembering

Test was done 24 hours after taking both T3 and T4 the previous day at 8:30 am.

In that case your results are showing a false low FT3 level. The day before the test last dose of T3 should be 8-12 hours before the blood draw (splitting dose into two).

But you have tested too soon, you need to leave 6-8 weeks for thyroid hormone levels (FT4 and FT3) to settle before retesting.

Taking T3 does lower TSH and often suppresses it.

buddy99 profile image
buddy99 in reply to SeasideSusie

Thank you, SeasideSusie. I will try again to split the dose. That's what I would have liked to do in the first place. Maybe my pill splitter is no good.

Ozziemum profile image
Ozziemum in reply to buddy99

My T3 leaflet (Teva) says you can grind it up and put it in water to dissolve it then syringe up half the amount so you get pretty much half dose then save the next half for later. I don't know if they're all the same though...

buddy99 profile image
buddy99 in reply to Ozziemum

Yes, I read that too and considered trying it. Thanks Ozziemum.

Batty1 profile image
Batty1 in reply to buddy99

No your pill cutter is probably fine those T3 pills are super small and crumble no matter what you use to cut them.

buddy99 profile image
buddy99 in reply to Batty1

Thank you, Batty1. I'm glad somebody else has had this experience. After desperately trying different ways to divide those pills (including breaking them between thumb and index fingers, pre-scoring them with a very sharp knife etc. ) I felt a little, let's call it "incompetent". Even if others were able to do the task those pills had defeated me. :D I am looking into a different way of taking two doses a day. Very much appreciate your advice, though.

jimh111 profile image
jimh111

Have the blood taken about half-way between T3 doses to get an idea of average fT3 levels.

T3 is about 3x as potent as T4 in terms of suppressing TSH. I wouldn’t expect 5 mcg L-T3 daily to reduce TSH much. Possibly you have thyroiditis and your thyroid has erratic secretion?

buddy99 profile image
buddy99 in reply to jimh111

Thank you, jimh111. I do have hashimoto's thyroiditis. Had it for almost 50 years and my thyroid is pretty well shot. My TSH tends to fluctuate a little bit but not like that. I wish I could split the pills in half to take two doses but at this point I have not found a good way to do it.

jimh111 profile image
jimh111 in reply to buddy99

I snap tablets between my forefingers and thumbs. The halves don't have to be equal.

buddy99 profile image
buddy99 in reply to jimh111

I will try that. Thanks.

KBA22 profile image
KBA22 in reply to buddy99

I bought a pill cutter on Amazon. Really easy to use. They might sell them at a local pharmacy too.

buddy99 profile image
buddy99 in reply to KBA22

Yep, so did I. I also tried my daughter's pill cutter. No luck. The pills just crumbled into chalky powder.

Sus64 profile image
Sus64 in reply to jimh111

I only take one dose of T3 in the morning, so if I test in the morning, that means 24 hours have passed. I don't know whether I need a second dose, or, if I should take that daily dose just at night only prior to a morning test? I'm still working on levels.

jimh111 profile image
jimh111 in reply to Sus64

If you find it difficult to split the dose you could switch to taking your T3 in the evening. Also bear in mind you are on a fairly low (but physiological) dose so your T3 will have a small effect on your blood test results provided you leave at least four hours between your last dose and taking the blood.

Sus64 profile image
Sus64 in reply to jimh111

Great, thanks very much.

Clairewalker751 profile image
Clairewalker751

My TSH has always been suppressed since taking T3 and I only take 3mcg per day, I split a 25mcg tablet into 8 😲 cheapest option as I self medicate, I stopped the T3 once for about 6 weeks and felt dreadful but my TSH crept back up

arTistapple profile image
arTistapple in reply to Clairewalker751

I am glad you posted this Clairewalker751? As I said to buddy99, it’s the ‘official’ testing that is a bit of a nightmare. I know I am getting better at fighting my corner but it’s always a bit of a thought. How long did it take for you to feel better after recommencing your T3 after your six week break?

Clairewalker751 profile image
Clairewalker751 in reply to arTistapple

Seemed to take forever but I would say about 8-10 weeks of being back on T3 before I felt fully well again, I've never asked for my results of GP bloods as I suspect they only test TSH, surprised GP has never contacted me to reduce levo dose with my suppressed TSH but they haven't in the last 4 years

arTistapple profile image
arTistapple in reply to Clairewalker751

Ooh Clairewalker751 maybe you have a particularly ignorant GP. It’s working in your favour in this instance. Keep well!

buddy99 profile image
buddy99 in reply to Clairewalker751

Wow! That is AMAZING. Are the 25mcg pills bigger than the 5mcg? What is your method? As I said, I can't even cut the Teva 5mcg in HALF. Trying to cut them into 8 pieces would be a nightmare for me.

Clairewalker751 profile image
Clairewalker751 in reply to buddy99

I use a pill cutter to split them into 4 then use my nails to split the quarters in half, I'm sure it's not exact but I basically take 25mcg over 8 days

buddy99 profile image
buddy99 in reply to Clairewalker751

Your pills must be different from mine. The pill cutter does not cut it. It just crushes it. ;)

arTistapple profile image
arTistapple

It’s the testing, whether we are officially on T3 or unofficially, which is nerve wracking. If we are not able to fight our corner with the GP or possibly an endo, this is the issue - presumably if you are getting on fine with T3 in the first place.

WhyAmISoTired profile image
WhyAmISoTired

I was on 10mcg of t3 for a while and my tsh was around 1, so it's not necessarily the case that tsh is suppressed when on t3, but I know it happens to many people on here.

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