Reducing thyroxine from 100 mcg to 75 mcg

[Tjqui00]

My recent blood test is: FT4 18.4 (range 7.9-14.4) FT3 6.6 (range 3.8-6.0) TSH <0.02. My TSH always seems to be this no matter what dose I’m on. I was on 150 mcg years ago and have been gradually reducing my dose mainly because of my TSH when other results were in range. In 2023 my FT4 went above range and I reduced my dose to 100 mcg on 2 days, then 125 mcg on the 3rd day. Then my FT4 went even higher with after the reduction. So I then reduced it to 100 and it’s still over range. Do you think I need to reduce it to 75 mcg as it seems a big reduction to me. I’d rather reduce it more gradually but my doctor won’t agree to let me.

[greygoose]

As you have Hashi's, your high levels could be more down to that, than to your dose of levo. So, the level could reduce and leave you hypo again. If you do decide to reduce your dose even further, make sure you have the option of putting it up again if needed.

[tattybogle]

normally i'd prefer to adjust by no more than 12.5mcg / day.

but when both fT4 are fT3 are over range , and there is a clear pattern of fT4 rising by itself for whatever reason , then in this instance maybe 25 is ok.

but it does rather depends on how you feel .... ie. if currently feeling rubbish and have any symptoms that could possibly be overmedication. then i'd reduce by the full 25mcg now .

if currently feeling pretty good ... i'd just do 12.5 for now , and re-asses after another 2/3 mths .

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

just for interest:

co-incidentally the same thing has been happening to me for a few yrs now .... FT4 keeps going up and over range , despite several small dose reductions over time.

i was on 150mcg for 14 yrs, then became overmedicated (with symptoms) so reduced to 125 . symptoms of overmedication went away

ok for couple of yrs , then fT4 rose to top of range ... then next year went higher to 20 [7.9-14] 206 % ( i felt fine though)

reduced to 112.5mcg (which made me feel lousy) ... 3 mths later fT4 had risen to 22.7 [7.9-14] 242%

reduced very gradually from 112.5mcg to 100mcg ... 6 mths later fT4 was lower but still way over range 19 [7.9-14] 181% (100mcg dose led to chronic constipation/ zombie )

GP reluctantly put back up to 112.5mcg at my request. (constipation then resolved)

Then 6 mths later (despite putting the dose put up to 112.5mcg) the ft4 had lowered to 16.6 [7.9-14[ 142%

(and my TSH surprised me by rising to 1.9 , (it has been around 0.05 to 0.6 for 20 yrs)

then didn't test for a couple of yrs since i was functioning ok , and kept to same dose

then 3 yrs later reduced to 100 as an experiment.

after 4 months on 100mcg fT4 15.7[7.9-14] 128% .... but TSH was 2.6

so retested 3 mths later to check ,, still fT4 same , TSH lowered a bit to 1.6

so am currently trying 87.5mcg ...strangely no constipation , but don't feel great though.... not tested yet ..... will be interesting to see what results are when i get round to it in a week or so.

I don't have an explanation for my fT4 rising like it has ...... but my conversion of T4 to T3 has got worse .. fT3 was usually around 5 when T4 top of range on 125mcg a few yrs ago , but recently on 100mcg it was staying at 4 ... which may explain why my TSH is higher than it has been in the past, so it's starting to look like it might be time for me to to try a bit less levo with a bit of added T3, but haven't decided yet.

[Tjqui00 in reply to tattybogle]

I don’t feel ill, i feel fine. They want my TSH in range but I dint think it ever will. I can’t remember it ever being in range or not for many years.

[tattybogle in reply to Tjqui00]

on it's own, that TSH wouldn't really bother me , i'd prefer it a tad higher ie. over 0.04 but i don't see any need for TSH to be 'in range'

so if fT4 / fT3 were ok i wouldn't reduce dose if i felt well .

but your fT4 is pretty high and getting your ft4 lower is probably a good idea for various reasons ( eg higher T4 levels recently found to be associated with cell proliferation in some cancers etc ).

but as you feel ok , i'd only reduce to 87.5mcg and see what happens ... in my opinion reducing to 75 is a big drop and it could leave you feeling very unwell which is a big thing to risk if you currently feel well.

I wonder if the Doc would be so happy to insist you reduce by 25mcg if it was him who had the consequences and risked ending up struggling to manage at work, feeling lousy ?

some docs don't seem to understand the impact that even a very small dose change can have on how we feel.

[Tjqui00 in reply to tattybogle]

The conversation I had with him was by text only and I said I wasn’t comfortable reducing it by that much and I usually do it more gradually and he just replied saying he didn’t think it was much of a reduction. I’ve got a phone appointment with another doctor tomorrow, so hoping she’ll agree to let me reduce more gradually. I was going to ask if I could take 100 for 2 days and then 75 on the 3rd day. The doctor today had already prescribed 75 and sent it to pharmacy before speaking to me.

[Tjqui00 in reply to tattybogle]

your doctor let you increase your dose when you’re ft4 was over range then. I don’t think mine would and this doctor today originally only wanted TSH tested and I think he will dose on that. He said if this still doesn’t reduce enough, he’ll look at reducing my dose more.

Do you have hashimotos?

[tattybogle in reply to Tjqui00]

yes , you can fine tune doses by alternating days

eg 100/75/100/ 75 etc .. which gives dose of 87.5/ day .

or 100/100/75/ 100/100/75/100 etc

it's very common for doctors to prescribe like this to get smaller adjustments than 25mcg ... doctors with more experience of treating hypothyroidism know that for some people 12.5mcg is enough to make a significant difference to how they feel and to blood results.

[Edited later ]

yes i have autoimmune hypo. went wrong age 32 after 2nd pregnancy.

[Tjqui00 in reply to tattybogle]

Mine went wrong after first pregnancy when I was 26.

Trouble is, the doctor said to book a blood test in after 6 weeks. I suppose I can try delaying it, I’ve done that before. I’d need to agree with them what dose I’m going to go on first.

[SlowDragon Administrator]

when did you last test vitamin D, folate, ferritin and B12

What vitamin supplements are you taking

[Tjqui00 in reply to SlowDragon]

I’ve never had vitamin D tested but had ferritin and B12 tested a year ago.

[SlowDragon Administrator in reply to Tjqui00]

So these need testing

[Tjqui00]

I’ve never had vitamin D tested. I had B12 and ferritin tested a year ago.

[Tjqui00]

spoke to another doctor who said to take 100 for 2 days and then 75 on 3rd day for a month and then a month taking 100 and 75 the next day and then test. Do you think that’s ok and gradual enough? Don’t like the thought of going down under 100 after 20 years above it.

She said my TSH was last in range a decade ago and if after reducing my dose and T3 and T4 are in range but TSH is still suppressed, then she needs to get advice from endocrinologist. My T3 and T4 up to a year ago were in range but TSH suppressed so not very hopeful it will change.