Aa
Aa
A
A
A
Close
Avatar universal

Discrepancy between T4 levels and clinical response

Hi everyone!

I am really happy that I've found this website!
I am 36 y/o, and I've been through a thyroidectomy in dec/2010 because I had too many nodules on my thyroid - all of them benign. I've been under Euthyrox since then, and that's what brought me here.
My discussions with my doctors are endless because when we settle with 112mcg dosage of Euthyrox, I feel fine. With 125mcg, I feel very good, specially because I run a lot, and with 112mcg I simply don't feel the stamina to run everyday. But 112 is ok, really - I run, I work, and I'm able to live an active and productive life.
However, when under 112, my T4 levels are always above the acceptable range (i.e, beyond 21, normally between 22-25). So the doctors always lower my dosage to 100mcg, which renders acceptable t4 levels on my blood tests, but makes me feel sluggish, unfocused, etc.
I really don't know what to do, really. I'm afraid to insist on a higher dosage and in long term harm myself (with problems such as bone loss), But it's terrible to study and work having to struggle to get out of bed.
Have any of you ever been through something like this?
I'd love to hear from your experiences and ultimate treatments!

Cheers,

Francis
Best Answer
Avatar universal
First thyroid does not cause bone loss.  THyroid levels affect the metabolism rate and the faster matabolism may cause the rate of bone loss to increase.  THe bone loss itself is from a nother cause.

Second if you could please provide your lab results and also include the reference ranges.

All that being said. many people find that they need their FT4 levels to be in the MIDDLE of the range or slightly higher AND (that means in addition to) their FT3 levels to be in the UPPER 1/3 of the range in order to feel well.

Every person is different and they will be optimized at different levels.  YOU need to find out where you feel the best and it sort of sounds like you know where that is.

I would encourage you to get a free T3 level and get that done each time as well as your Free T4 level.

Your body ONLY uses free T3 (FT3) at the cellular level.  So it makes sense that you will want to test the very thing your body uses.

Finally some have suggested and I have read previously that stress including strenuous exercise can also cause some issues with Reverse T3.  Not saying this is a problem for you.  

Reverse T3 is made ONLY from the conversion of T4 into the usable T3.  During the conversion some of it is made into Reverse T3 which looks so similar to Free T3 that the cells can receive the RT3 molecule but it is biologically inactive.  Too many RT3 molecules plug up the cells and thus won't let enough FT3 to do the work.

You can have RT3 tested if you think this may be an issue.  Generally one way to determine if it may be an issue if your FT3 levels are lower than FT4 levels in their respective ranges.
7 Responses
Sort by: Helpful Oldest Newest
Avatar universal
@Barb135 Thanks a lot for the tips. I thought about that, and I'll suggest it to my doctor. The thing is, I'm living in Norway now, and they don't have .112. What I'm actually taking is 100mcg/125mcg on alternate days. So to get 106 will involve a bit more of trouble, but we'll cross that step when we get there.

@flyingfool Thanks again. Those results are indeed from when I take 112 and feel well. I've written to my Brazilian doctor (as I haven't seen an endocrinologist yet here in Norway, though my GP is being extremely understanding and helpful) and I've pointed out all these possibilities. It worth a shot, right? I'll be seeing an endocrinologist here in Norway in july, right after get another lab results by the end of june (to assess how it was under 100mcg).

Can't thank you folks enough!
Helpful - 0
Avatar universal
A couple of things.

first we still don't know if the testing you are getting is for FREE or for TOTAL T3 and T4

If we look at your ranges you posted above:
T4: 25,3 (range: 8-21)
T3: 4,1 (range 3,5-8,3)

The T4 is over 100% of the range  while the T3 is towards the very bottom of the range at only 12.5% of the range.

This suggests a significant conversion problem.  That is your body is NOT converting the T4 into T3 well.

People who have a conversion problem usually feel well when they add a source of T3 medication to make up for the loss of conversion.

What I'm suggesting you talk to your Dr about is the thought of reducing your T4 and ADDING a source of T3 medication.  Another alternative would be to switch to natural dissected thyroid. But I would tend to favor the idea of reduced T4 and addition of synthetic T3.

Are the levels listed above when you were on 112 mcg T4 and you were feeling well?  If so then you may have somewhat of a target to shoot for.

By reducing your T4 medication you can adjust your T4 to the middle of the range AND you can get your T3 levels up enough so that you feel well.  This I would hope would make BOTH you and your Dr feel comfortable as the Dr will have the labs within range, and you will feel well.

Making the dosage adjustments to get to this optimized state may take some time but I would think well worth the effort!

Something to think about.
Helpful - 0
649848 tn?1534633700
COMMUNITY LEADER
We're all different, and some people's "normal" might actually be higher or lower than the reference ranges.  

"I know it's always a question of subjectivity, but I don't feel I should take a higher dosage to feel a bit hyper, which happened when I took 125. I just would like a dosage that doesn't make me drag myself to do my daily stuff."

Maybe you could try alternating 100 and 112 for an average of 106.  Sometimes, it only takes a tiny tweak, to make a huge difference.

Many doctors won't run RT3.
Helpful - 0
Avatar universal
Everybody, thanks a LOT for your answers - it's just great to have such quality feedback!

@flyingfool - I didn't mean thyroid causes bone loss, I said I was concerned about taking a higher dosage of T4 would cause so. My last results are:
T4: 25,3 (range: 8-21)
T3: 4,1 (range 3,5-8,3)
TSH: 1,62 (range: 0,5-3,6)

So, it make sense the possibility of the RT3 being an issue. I'll definitely ask the doctor to prescribe a test for that as well! Thanks a lot for pointing that out!

@Red_Star - thanks a lot - it's relieving to see that there are other ranges that could be considered, and that the risk might not be that high!

@Barb135 Thanks for your answer! What I meant was that, when I am taking a dosage of 112mcg T4, I feel fine, but my levels are higher than the acceptable range (as shown above). So the doctors reduce my intake to 100mcg, and, while the levels normally are fine when taking such dosage, I feel sluggish.

I know it's always a question of subjectivity, but I don't feel I should take a higher dosage to feel a bit hyper, which happened when I took 125. I just would like a dosage that doesn't make me drag myself to do my daily stuff.
Helpful - 0
649848 tn?1534633700
COMMUNITY LEADER
Many doctors don't test for Free T3, but they almost always test TSH, with T4 (is that free or total?).  Do you have TSH results? We don't put a lot of importance on those, because TSH is variable, but it's nice to have the whole picture.

I'm sorry, I don't understand this comment: "However, when under 112, my T4 levels are always above the acceptable range (i.e, beyond 21, normally between 22-25). So the doctors always lower my dosage to 100mcg, which renders acceptable t4 levels on my blood tests, but makes me feel sluggish, unfocused, etc."   Your T4 level should go down when you reduce below the 112 and up when you increase; not the other way around - or am I reading it wrong?

Some people need to be slightly hyper to feel well.  Of course, this makes doctors uncomfortable.  

I've read that too high levels of FT3 can cause osteoporosis but I'd have to find links for it.
Helpful - 0
1756321 tn?1547095325
My friend from Holland told me his free T4 range is 11 - 25pmol/L.  Mine is a bit lower at 10 - 20 pmol/L. Pretend you live in Holland. :)

"Bone Density After Long-Term Suppressive Thyroid Therapy By Mary Shomon

Korean researchers have evaluated the impact of long-term suppressive levothyroxine therapy on bone mineral density (BMD) and bone turnover markers in women who were thyroid cancer survivors.

The study looked at almost 100 women who were on levothyroxine for at least 10 years after thyroid cancer. They were divided into three groups: TSH less than 0.001, TSH between 0.001 and 0.07, and TSH levels above 0.07. The BMD was measured by dual-energy X-ray absorptiometry (DEXA) scanning.

The research found that there was no significant decrease in BMD and bone turnover markers among the women, and the prevalence of osteoporosis and osteopenia was not different among the groups.

The researchers concluded that long term suppressive levothyroxine therapy for thyroid cancer management did not affect bone density or increase the prevalence of osteoporosis.

Source: Lee, M. et. Al. "Bone Mineral Density and Bone Turnover Markers in Patients on Long Term Suppressive Levothyroxine Therapy for Differentiated Thyroid Cancer," Abstracts of the American Thyroid Association Annual Meeting, 2011"
Helpful - 0
Have an Answer?

You are reading content posted in the Thyroid Disorders Community

Top Thyroid Answerers
649848 tn?1534633700
FL
Avatar universal
MI
1756321 tn?1547095325
Queensland, Australia
Learn About Top Answerers
Didn't find the answer you were looking for?
Ask a question
Popular Resources
We tapped the CDC for information on what you need to know about radiation exposure
Endocrinologist Mark Lupo, MD, answers 10 questions about thyroid disorders and how to treat them
A list of national and international resources and hotlines to help connect you to needed health and medical services.
Herpes sores blister, then burst, scab and heal.
Herpes spreads by oral, vaginal and anal sex.
STIs are the most common cause of genital sores.