Could somebody help me to interpret my blood te... - Thyroid UK

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Could somebody help me to interpret my blood test results?

Ania22 profile image
14 Replies

My FT3 remains high while FT4 is always very low. I take NDT.


Serum free T3 level 7.3 pmol/L (3.5 - 6.5) Abnormal

Serum free T4 level 13.2 pmol/L (9.0 - 22.0)

Serum TSH level 1.00 mU/L (0.10 - 4.00)


18.02 only on NDT (1 gram of NDT)

FT3 4.22 (3.1-6.8)

TSH 3.51 (0.2-4.3)

T4 80 (66-181)

FT4 12.1 (12-22)


ferritin 49.1 (13-150)

FT3 7.21 (3.1-6.8) abnormal

TSH 1.39 (0.2-4.3)

T4 88.7 (66-181)

FT4 11 (12-22)

28.04 (1.5 gram on NDT)

FT3 6.7 (3.1-6.8)

TSH 1.91 (o.2 - 4.3)

T4 90 (66 - 181)

FT4 10.5 (11-22)

14 Replies
Lalatoot profile image

Some folks manage with a top of range FT3 and low FT4. Others need their FT4 well over half way through range along with their FT3 to feel well.

If you are symptomatic and feel a higher FT4 is needed then you will need to add some levothyroxine.

As your FT3 is at the top and sometimes over range you may want to reduce NDT a little first as adding T4 will increase FT3 a little depending on how well you convert.

Ania22 profile image
Ania22 in reply to Lalatoot

FT3 is a little bit over range. Can it be toxic in any way?

I still get symptoms, this might be the reason.

Thank you for your reply.

Ania22 profile image

FT3 is a little bit over range. Can it be toxic in any way?

I still get symptoms, this might be the reason.

Thank you for your reply.

greygoose profile image
greygoose in reply to Ania22

Lalatoot won't see this reply because you did not click on the blue 'Reply' button beneath her comment. I've notified her for you. :)

So, how much NDT were you taking at the time you tested on 21.05? I wouldn't describe excess T3 as 'toxic' exactly, not at that level. Many people need their FT3 slightly over-range to feel well. But you wouldn't want it very high for very long. That would be bad for your heart. But, I don't think you need to worry at your level.

Why are you testing every month if you're not changing your dose? And, if you are changing your dose, you need to be on that dose for six weeks at least before testing.

FT4 will always be lower on T3 than if you took T4 only.

Ania22 profile image
Ania22 in reply to greygoose

I was taking 1.5 gram of Nature Thyroid and 12.5mg (half of 25mg tablet) of Levothyroxine.

I started taking LDN from around November. At first I moved from 2 grams to 1 gram of NDT but since I became pregnant I needed to increase my dose....

greygoose profile image
greygoose in reply to Ania22

I think you mean 'grain', not 'gram'. NDT is measured in grains.

That's a lot of chopping and changing in a very short time. Which, means that your monthly blood tests are not going to tell you the full story. I think you need to stop changing your dose, and stay on the dose you're taking now for the next six weeks, and then retest, see where you are.

Lalatoot profile image
Lalatoot in reply to Ania22

High FT3 can cause symptoms.

DippyDame profile image
DippyDame in reply to Lalatoot

People with thyroid hormone resistance need a high dose of T3 with high FT3....mine sends medics running for the hills! But I need it to be high to function....scientifically proved.

But you're right, high FT3 should otherwise be avoided

DippyDame profile image
DippyDame do you feel?

Are you self medicating?

Why are you taking NDT?

When did you start taking NDT? 18 Feb?

1 grain NDT contains 9mcg T3 and 38mcg T4

How well do you convert T4 to T3?

The T3 in NDT is raising your FT3....although some people need high FT3 if they have a type of hormone resistance. I am one.

Your ferritin is too low

Have you tested folate, vit D and vit B12

These nutrients should all be optimal for good conversion and thyroid health

I suggest that first, you test your nutrient levels, optimise them and you might try lowering the NDT and adding some levo.....but difficult to say without pre NDT labs

Do you have a copy of your diagnostic labs (first test before medication) if so post a copy for advice. This will help evaluate your thyroid status?

Sorry, so many questions but the answers provide the clues !

I'm not a medic just somebody else who has travelled the bumpy thyroid road looking for answers.

Good luck



Ania22 profile image
Ania22 in reply to DippyDame

I am taking NDT for around 3 years but only recently started taking LDN (lower dose naltrexone), whcih helps with autoimmunity.....

I started taking iron pills.

I have tested B12 on the 25.04 privately, Thriva B12 result came back 266 (300-570 normal range) and I was advised to suplement with vit B 12

1 week before (20.04) I had a test NHS tests:

B12 : 446 (160-820 normal range)

folate 16.5 ( >>4.1)

ferritin 25ug (10-291)

Angel_of_the_North profile image
Angel_of_the_North in reply to Ania22

B12 was still lower than optimal - needs ot be at least 500, ferritin pretty bad - needs to be about 70-80. Folate OK. But if your vitamin levels have got better, your conversion of T4 to T3 has probably improved.

DippyDame profile image
DippyDame in reply to Ania22

Have you found LDN beneficial? Hope it helps with your Hashi's.

Your B12 is, as you know, far too low....I expect you've seen this article from Thriva

I use a B12 spray from "Better You" (Amazon) recommended by another member.

I sympathise with your reaction to iron pills, I've never found a really satisfactory solution, though magnesium citrate does help. I stir it into my breakfast orange juice!

Magnesium baths can also help.

Medics know very little about the importance of nutrients and how they support the body's functions....."just eat a well balanced diet" is often their advice ! Hmmmm!

Keep an eye on your FT3 result it may help to lower your NDT a little. You need to leave 6-8 weeks between a change of dose to allow the body to adjust to the change, I think your body may be a bit confused by all the recent changes you've made!

I'd suggest saying on current dose for a few weeks while you optimise your nutrients

Just a few thoughts, others probably have better suggestions!

Ania22 profile image
Ania22 in reply to DippyDame

Thank you DippyDame for many questions......They are very helpfu.

I always had low ferritin, keep taking iron pills but stop taking them from time to time as they make me constipated!

Ania22 profile image


I found LDN beneficial...

I feel better but ufortunately still get the same symptoms. I feel calmer when taking LDN.

I have a lot of energy one day and then next day I am like a flat tyre...but I do not have any muscle, shoulder pains as I used to have previously.

I will read those articles. I had B12 tested by NHS around 3 years ago, it came back as normal apparently....I did not know any better....

I actually thought that my B12 is slightly too low after looking at the recent tests.

Thank you for all your advice.

I try to eat chicken liver every so often, take 50mg iron pills which not supposed to cause constipation in fact...well, at least i know that my iron is low....

Apparently some people buy dried liver....I never checked it....

Would you say that I do not need to be worried about slightly higher FT3?

Thank you:)

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