Low TSH low FT3: Hello everyone! I have a... - Thyroid UK

Thyroid UK

141,510 members166,850 posts

Low TSH low FT3

roukounasGK profile image
13 Replies

Hello everyone!

I have a question that your experience may help with.

My latest Labs showed a normal thyroid function but not optimal (low TSH and a low ft3). The values are:

TSH: 0,5 with a range of 0,5 - 4,5

Ft3: 3,6 with a range of 3,1 - 6,8

This has never happened again to me before. I am experiencing hypothyroid symptoms (fatigue, light-headed etc).

I only take levo (t4).

My dr says that I am fine, and the optimal course of action is to decrease the t4 dosage. But If I am afraid to do so (which I am) it's ok to leave it as it is. In no way should I take t3 medication.

Has this happened to anyone else? Is this something temporary I should wait or something permanent? How did you increased the ft3? Is there any way to naturally increase it (Supplements etc.)?

Any personal feedback would be helpful!

Written by
roukounasGK profile image
roukounasGK
To view profiles and participate in discussions please or .
Read more about...
13 Replies
Lalatoot profile image
Lalatoot

It would be helpful to know your ft4 result. By comparing ft4 and ft 3 we can see if you have a problem converting t4 to t3. That would be my guess when tsh and Ft3 are low.

roukounasGK profile image
roukounasGK in reply toLalatoot

Yeah, I completely agree with you. But the Dr did not order this test. I am planning to do so privately next week. I just asked In case anyone has experienced this before and if so, how they handled it.

SlowDragon profile image
SlowDragonAdministrator in reply toroukounasGK

You need to test all three together - TSH, Ft4 and Ft3

Do test as early as possible in morning before eating or drinking anything other than water and last dose levothyroxine 24 hours before test

As you have Hashimoto’s it’s important to regularly retest vitamin D, folate, ferritin and B12

roukounasGK profile image
roukounasGK in reply toSlowDragon

Hey SlowDragon ,

Thanx for your tips. I have these in mind. Vitamin D, ferretin and B12 is always optimal so my Dr didn't see the need to retest them. Folate i did test this time around and is normal (though on the low side):

Folate: 4,7 with a range of 4,6 - 18,7.

SlowDragon profile image
SlowDragonAdministrator in reply toroukounasGK

Folate is low

Supplementing a good quality daily vitamin B complex, one with folate in not folic acid may be beneficial.

chriskresser.com/folate-vs-...

B vitamins best taken after breakfast

Looking at your profile, you are in Greece?

Not sure what vitamins you can get there

UK we recommend

Igennus Super B is good quality and cheap vitamin B complex. Contains folate. Full dose is two tablets per day. Many/most people may only need one tablet per day. Certainly only start on one per day (or even half tablet per day for first couple of weeks)

Or Thorne Basic B or jarrow B-right are other options that contain folate, but both are large capsules

If you are taking vitamin B complex, or any supplements containing biotin, remember to stop these 7 days before any blood tests, as biotin can falsely affect test results

endo.confex.com/endo/2016en...

endocrinenews.endocrine.org...

Lalatoot profile image
Lalatoot in reply toroukounasGK

That is strange that he did not ask for it as it is more commonly tested than FT3. they usually test TSH and FT4 and ignore FT3.

Low TSH and low FT3 is a scenario that is often seen on this site.

My results were:

TSH 0.19 (0.55 - 4.78)

FT4 19 (10 - 25)

FT3 4.5 (4.0 - 7.0)

By comparing FT4 (60% through its range) and FT3 (only 16.7% through its range) I was able to demonstrate that my body was not effectively using the FT4.

This has enabled me to get more effective treatment.

roukounasGK profile image
roukounasGK in reply toLalatoot

It did seem a bit strange to me as well. I will do so next week and come back here with more info. What was this effective treatment? T3 medication I assume?

Lalatoot profile image
Lalatoot in reply toroukounasGK

Yes combination of levo and liothyronine. Taken 9 months for me to feel that I am getting there.

SlowDragon profile image
SlowDragonAdministrator

What is your Ft4 result?

TSH: 0,5 with a range of 0,5 - 4,5

Ft3: 3,6 with a range of 3,1 - 6,8

Bloods should be tested as early as possible in morning before eating or drinking anything other than water and last dose levothyroxine 24 hours before test

You need Ft4 result ....if Ft4 is low you need dose increase in levothyroxine

If Ft4 is high in range then you have poor conversion of levothyroxine into Ft3

Improving all four vitamins helps improve conversion of Ft4 to Ft3

So you need ferritin tested

roukounasGK profile image
roukounasGK in reply toSlowDragon

From the last post I did measure ft4

The result was 16,5 on a range of 10-23. The rest of my labs were almost as previously mentioned, i.e.

TSH: 0,8 range: 0,5-4,5.

Ft3: 4,5 range: 3,1-6,8

Do these results show conversion issues on your opinion? Or just low dose?

SlowDragon profile image
SlowDragonAdministrator in reply toroukounasGK

So Ft4 is only 50% through range

Ft3 only 38% through range

Helpful calculator for working out percentage through range

chorobytarczycy.eu/kalkulator

Dr Toft, past president of the British Thyroid Association and leading endocrinologist, states in Pulse Magazine,

"The appropriate dose of levothyroxine is that which restores euthyroidism and serum TSH to the lower part of the reference range - 0.2-0.5mU/l.

In this case, free thyroxine is likely to be in the upper part of its reference range or even slightly elevated – 18-22pmol/l.

Most patients will feel well in that circumstance.

But some need a higher dose of levothyroxine to suppress serum TSH and then the serum-free T4 concentration will be elevated at around 24-28pmol/l.

This 'exogenous subclinical hyperthyroidism' is not dangerous as long as serum T3 is unequivocally normal – that is, serum total around T3 1.7nmol/l (reference range 1.0-2.2nmol/l)."

You can obtain a copy of the articles from Thyroid UK email print it and highlight question 6 to show your doctor



please email Dionne at

tukadmin@thyroiduk.org

Guidelines on levothyroxine dose by weight is 1.6mcg per kilo of your weight...rare to need less...some people need more..or addition of T3 if conversion is poor

If have Gluten intolerance often means we need addition of T3 alongside levothyroxine....obviously that’s cheap and easy in Greece (unlike here in U.K.)

roukounasGK profile image
roukounasGK in reply toSlowDragon

1,6 per kg? This seems very much! I am now 100 kg, so based on these calculations I need more than 1,5 mcg. And when I was feeling great with my health, prior to reducing my dose, I had 1,25!

So I am sure to increase it then, at least to 1,25 and see how it goes. My Dr though reluctant is discussable so he may help me if I present these facts. And even if he doesn't agree I can try it myself and present to him my new labs once I do. Thanks a ton!

Finally regarding the t3 I have thought of it myself. It is indeed cheap and easy to get in Greece. But once I mentioned it to my endo, it was out of question. He was very negative on taking t3. And since I don't have a clue on how to take it, dosage, effect on my body etc. I am reluctant to self medicate without his approval (at least in the beginning).

Is there any beginners guide for taking t3 along with levo?

SlowDragon profile image
SlowDragonAdministrator in reply toroukounasGK

Marz may have advice on finding a better endo in Greece ...

Read posts on here re T3...but it’s easier to manage on just levothyroxine, if you can, but obviously needs to be high enough dose

If can’t tolerate higher dose, then looking at adding T3 instead

Not what you're looking for?

You may also like...

Low fT4, but midrange fT3. Feeling cold, brain fog.

Hi there, male, 64, fit, no problems besides this: for about 3 years I´m having symptoms like...
gd33 profile image

Still feeling cold on Levothyroxine. Low Ft3, add T3?

Hello, I got diagnosed with subclinical hypothyroidism half a year ago. TSH slightly elevated and...

Low TSH, FT4 & Ft3

I am taking 50 mcg OF T4 & 25 of T3 , My results from a couple days ago are: TSH 0.40—4.50 miU/L...
GKeith profile image

Low tsh

I have many run ins with my gp after thyroid blood tests which obviously are only done annually and...
jodary profile image

Lower T4,T3,FT3,FT4,TSH after taking Levo

Hi all! I am really desperate and clueless about a solution. My physchology is getting worse as I...
Cofy profile image

Moderation team

See all
Buddy195 profile image
Buddy195Administrator
PurpleNails profile image
PurpleNailsAdministrator
RedApple profile image
RedAppleAdministrator

Content on HealthUnlocked does not replace the relationship between you and doctors or other healthcare professionals nor the advice you receive from them.

Never delay seeking advice or dialling emergency services because of something that you have read on HealthUnlocked.