# Bit stuck on thyroxine dose



## Sue (Mar 30, 2015)

Hi All,

I'm 5 1/2 years after Total Thyroidectomy but I'm a bit stuck with my thyroxine doses. Here's the relevant data:

2017 numbers:

*TSH mU/L*

*T4 (reference range 12-22) *

Thyroxine dose&#8230;..100 three days a week 75 four days​
Jan

0.35

15.7

June

0.16

19.8

July

0.07

16.6

Thyroxine reduced to 100 two days a week 75 five days​ ​
November

0.18

20.3

My TSH goal is 0.3 - +2. So in theory I should decrease thyroxine a bit more. And we are now told (in the UK) that it's important to do that as long term suppression of below even 0.5 mU/L is bad for heard and bone . But as I reduce thyroxine I get well slug like!

Any advice?


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## Sue (Mar 30, 2015)

I'm so sorry, those numbers have not formatted right. Let me try again:

2017:

January: TSH 0.35 T4 15.7 (thyroxine dose 100 *three *times a week and 74 four times)

June: TSH 0.16 T4 19.8

July: TSH 0.07 T4 16.6 (thyroxine reduced to 100 *twice *a week and 75 five times)

Nov: TSH 0.18 T4 20.3


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## Lovlkn (Dec 20, 2009)

> My TSH goal is 0.3 - +2. So in theory I should decrease thyroxine a bit more.


If you want to lower TSH then an increase is what you need, not a decrease.

I would also suggest you look at the FT-4 result in addition to the TSH result. TSH is going to move more than FT-4 so don;t get too hung up on the exact suppression number and rather the fact that it's suppressed


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## joplin1975 (Jul 21, 2011)

Yup, agreed!


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## Sue (Mar 30, 2015)

I'm 5 years post surgery now so I'm supposed to be moving into the normal range rather than suppressed range. I've been given 0.3 - +2 as my goal but with the caveat that you can have bone effects even on a TSH of 0.5.

So in theory I simply lower my thyroxine dose and that will get my TSH up into the normal range.

But I'm learning that it's a lot more complex than that as Free T4 and T3 are important also as well as TSH in deciding what to do.

In plain English is this the relationship - thyroxine makes T4 in the body. However you can't assume that a high T4 means all is good. Free T3 is the form of the hormone that the body can use. So you need to test Free T4 and T3 and you need T4 and T3 to be high. Is that right? I'm struggling with the T4/3 difference I think.


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## Lovlkn (Dec 20, 2009)

Goal is to adjust med's to achieve close to 3/4 of range during lab draw for both FT-4 and FT-3.

T4 hormone becomes FT-4 then FT-3. Having too high of a FT-4 is not a good thing and can cause symptoms of being hyper .


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## joplin1975 (Jul 21, 2011)

Correct. You can't rely on free t4 alone because when you body needs extra hormones (or energy), it converts t4 to t3.

For some reason, people with thyroid issues often don't convert t4 into t3. Or, at least not effectively.

A low TSH has no real impacts. A low TSH with a free t4 and free t3 above 75% of the range IS dangerous.


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## Sue (Mar 30, 2015)

Getting it (slowly!) and really grateful for the help.

So now that I'm past the 5 year point at can ease back a bit on meds the goal should be to NOT worry about TSH right, but keep FT4 and FT3 at about 75% of the range right?

And if I've understood what you've said correctly two of us could have very similar TSH levels but we will feel very different depending on our FT4 and FT3.

I've read that T3 can rollercoaster depending on many factors but is FT4 usually a valid measure of real FT4 or do you need a series to be sure of what's going on?

Again, many thanks!


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## joplin1975 (Jul 21, 2011)

Sue said:


> Getting it (slowly!) and really grateful for the help.
> 
> So now that I'm past the 5 year point at can ease back a bit on meds the goal should be to NOT worry about TSH right, but keep FT4 and FT3 at about 75% of the range right?


There's a looooooot of disagreement about this in the thyroid cancer community. I don't have a straight forward answer for you, unfortunately.

The latest longitudinal study I read said that spike in recurrence rates happen before the 5 year mark, at the 10 year mark, and at the 20 year mark. They were obviously making generalizations (i.e., its not like all ten year recurrences happened exactly at the ten year mark), but that was the general pattern. The take home message from that study is that ThyCa patients need life-long monitoring but also that we shouldn't get so comfy with backing off TSH just because someone is more than five years out.

I've talked to my endo and surgeon a lot about this and, while they rarely agree on much, they are both agreement that "just" hitting the five year mark isn't reason enough to change. IF you've consistently had undetectable Tg and TgAB, IF you've had no change on your ultrasound, IF you've consistently had clear whole body scans and IF you feel like your quality of life has suffered because of low TSH, it might be a good plan to think about letting that TSH come up a bit.

I've not had a recurrence nor do I feel like I'm at risk for one...but I'm also thriving on my levo dose. My TSH is low, but because my frees are in a good space, its not like the low TSH alone is dangerous. I'm not suffering quality of life issues, so we do not plan on making any changes.



> And if I've understood what you've said correctly two of us could have very similar TSH levels but we will feel very different depending on our FT4 and FT3.


Correct.



> I've read that T3 can rollercoaster depending on many factors but is FT4 usually a valid measure of real FT4 or do you need a series to be sure of what's going on?


Eh...kinda.

T3 is metabolized much quicker than t4. So when you take the t3 meds in relation to when you have your blood drawn (in addition to other factors like activity level) CAN impact your result. BUT, free t3 is critically important to "fine tuning" doses. As long as you are consistent as to when you take the med and when you get your blood drawn and you don't decide to do things like run a marathon without training the day before the blood draw, you can get consistent results which are infinitely helpful.

Free t4 is a bit more consistent and also important...but with both, a series of tests over time is the best way to measure things.


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## Sue (Mar 30, 2015)

It's just so..............well so damn hard really isn't it. I've been broadly happy running a TSH fairly low. But then I had a bone density and was found to have osteopenia. So by that argument drug dose must go down no question. In fact I took it down a bit for two years and just in that tie the osteopenia started to improve.

It's such a balancing act. Thanks goodness for this board which helps restore sanity.


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## joplin1975 (Jul 21, 2011)

Ah, that makes sense. In that case, yup, it makes sense to lower your dose.


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## Lovlkn (Dec 20, 2009)

Sue said:


> It's just so..............well so damn hard really isn't it. I've been broadly happy running a TSH fairly low. But then I had a bone density and was found to have osteopenia. So by that argument drug dose must go down no question. In fact I took it down a bit for two years and just in that tie the osteopenia started to improve.
> 
> It's such a balancing act. Thanks goodness for this board which helps restore sanity.


I also received an osteopenia DX a few years back. My TSH is always suppressed with 3/4 range or lower FT4 and FT-3. It's the FT-4 and FT-3 levels more than TSH in my opinion. I've read some studies that seem to agree.

My doctor told me alot of women have osteopenia and not to worry. I have not yet taken any pharmaceuticals to treat the boneloss as he states my activity is sufficient. I dread going on anything for it other than the 1500mcg calcium I take daily along with Vit D and Magnesium.


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## Sue (Mar 30, 2015)

If you ask a regular doctor (GP in the UK) they will all say that it's impossible to get osteopenia after taking thyroxine. If pushed they say that well after ten years maybe, theoretically, but highly highly unlikely. So if I went only to my GP I'd be still stuck on bone sapping doses of thyroxine. The consultant puts it differently - there are not that many studies that show it but YES without doubt even a few years of suppression can cause bone problems he says.


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