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Thyroid UK
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Lab Interpretation please?

Hi guys.. I finally was able to get my labs.

Labs 08/29/2016 9:12 am My last dose was taking 24 hs before the Lab. I was on 1 grain of NDT + 12.5mg T3 + T4 (levothyroxine) 50 mg

TSH: 0.01 0.40-4.50 mIU/L

FT4= 0.9 0.8-1.8 ng/dL

FT3= 3.5 2.3-4.2 pg/mL

Cortisol (bloodwork)= 10.4 mcg/dL

8.10 am 4.6-20.6 mcg/dL

4-6 pm 1.8-13.6 mcg/dL

PROLACTINE: 5.2 2.0-18.0 ng/mL

MEDICINE: NDT 1 grain + T4 (levothyroxine) 50mg + T3 12.5 mg

Hi, my Endo thinks I am hyper because my low tsh (0.01 L). He said I am Hypo as a basis but now I am hyper because he thinks I am taking "too much" medicine,so that's why he wanted to "reduce" my current levo T4 50 mg to 25 mg. I don't know how he can say that when my T4 is on 0.9 and normally to raise it up I would have to add even more NDT. However, I hate to say it but, I'm starting to believe him since I am getting shaking hands and my 3 pm basal temp is 98.9, so don't know what to do.


1) I have shown consistently a low FT4 even with the next dosages:

- 03/29/2016 2 grains NDT + T3 25 mg = FT4 0.8 range: 0.8-1.8 ng/dL ; FT3 4.1 range: 2.3-4.2 pg/mL

- 05/11/2016 3 grains NDT + T3 25 mg + T4 (levo) 50 mg = FT4: 0.9 0.8-1.8 (ng/dL) ; FT3: 5.3 High 2.3-4.2 (pg/mL)

- 07/06/2016 3 grains NDT + T3 25 mg + T4 (levo) 50 mg= T4 (NOT FT4) = 5.2 4.5-12.0 (mcg/dL)

- 08/29/2016 1 grain NDT + T3 12.5 mg + T4 (levo) 50 mg = FT4= 0.9 0.8-1.8 ng/dL ; FT3= 3.5 2.3-4.2 pg/mL

My FT3 is finally getting stabilized but my FT4 is still stubborn even with a high NDT dose. Should I raise it then to 4 grains?? Any thoughts?

2) I know the more accurate cortisol labs are the saliva ones but, he also said my cortisol levels were "good", but, shouldn't be them almost at the top of the range in the AM?

7 Replies

I've read that what cause a low FT4, but still good levels of T4 which is my case, is Sometimes due to an excess of thyroid hormone binding proteins, leading to a low Free T4, even though there is ample total T4. This could be caused by high thyroid binding globulin which is caused by high estrogen levels, pregnancy, or non-thyroidal illness. However, I am a male so I discharge the estrogen dominance in me as well the pregnancy. So the non-thyroidal illness would be the last thing to check. However, after reading the non-thyroidal illness says the FT4 is not only low but also the FT3 which is NOT my case, so I don't think I fit the glove.

BTW, do you guys know if this 'high thyroid binding globulin' are related to THYROGLOBULIN ANTIBODIES ? If does, I have them slightly high (42), or does it mean I am taking too much either NDT or T4? if does, it means my Endo is right and I am hyper. Any thoughts then?



TSH may be low when medicating NDT or T3 because the pituitary senses thyroid hormone in the blood stream and slows up. The T4 test result is not important when medicating NDT or T3 as it is the T3 level (bioactive hormone) that counts and yours is just over half way through range so you have room for improvement.

Not sure why you are medicating all three available med choices. Members usually have one choice, and maybe a second, if one hormone requires further titration.

You may require further T3 but you have had so many med changes. If this were me I would ditch the T4 & T3, medicate 2 & half grains of NDT which will give you the equivalent amount of T4 & T3 that you are now medicating, and test after six weeks, adjusting with extra T3 only if necessary.

Doctors consider adrenals shown to be working if results show enough activity but bloods measure both the active & inactive and the amount of free cortisol may prove inadequate for someone will many health issues. A saliva test will be more informative in showing you the bioactive amount secreted at differing times of the day, and knowing your cortisol pattern will allow you to supplement appropriately.

High thyroid hormone binding proteins can bind too much thyroid hormone so leaving it unavailable for use. Too little will leave too much thyroid hormone floating about in the blood stream which may block receptors. Balance is everything as all hormones within an axis depend on each other.

Just as a female can suffer from too much testosterone, being a male doesn't exclude you from elevated oestrogen, which balances testosterone. As you have been supplementing testosterone, it would be prudent to have sex hormones tested as a matter of course...

Thyroglobulin is a protein produced in the thyroid and a precursor of thyroid hormones, produced when thyroglobulin tyrosine combines with iodine and the protein is cleaved.

When we suffer damage (Hashimotos, Graves, etc), we can get thyroglobulin antibodies (TGAb). This result is of limited use as results are dependant on so many factors but is useful for those who have had their thyroid removed due to cancer. Having TGAb dose not mean you are overdosing with thyroid hormone meds.

Temps should improve when T3 is optimal


Wow radd. Pretty wise as always. Well, I decided to add some T3 since I "thought" I am not a good converter. I am not sure how to figure out that. I like your dosage formula. Even though I read yesterday that a good way to calculate the right dosage:

"For those of us who must take thyroid hormone because we do not have a thyroid gland due to thyroidectomy, radioactive iodine (RAI), etc., is there a mathematical way to determine our replacement dose? I recently found the article below and found the formula correlated well with people I know. A person’s weight in kilograms is multiplied by 1.5 to calculate the T4 dose in micrograms. This is expressed as 1.5 μg/kg.

Levothyroxine replacement dosage determination after thyroidectomy.

Four hundred four patients were included; 85% were women. The mean initial levothyroxine dosage was 1.4 μg/kg, which resulted in thyroid-stimulating hormone normalization in 59%, suppression in 23%, and elevation in 18% of patients. After dose adjustments, the mean therapeutic levothyroxine doses after total thyroidectomy and lobectomy were 1.5 and 1.3 μg/kg, respectively. A regression model incorporating other patient factors [age, sex, ideal body weight, body mass index, and body surface area] did not produce a more reliable dosing regimen. CONCLUSION: A 1.5- and 1.3-μg/kg dosage calculation based on actual weight is currently the best estimation for levothyroxine replacement therapy after thyroidectomy.

To apply this formula to yourself, you need your current weight in kilograms.

1 Pound = 0.45359237 Kilograms

I weigh 135 pounds, which is equal to 61.2 kg.

61.2 kg multiplied by 1.5 mcg = 92 mcg.

The closest prescription dose would be 88 mcg of levothyroxine, which just happens to be a dose I lived on for years after my RAI treatment! I believe that some amount of T3 is necessary to replicate normal thyroid gland output, and studies state that thyroid glands secrete T4 and T3 in a 10:1 ratio. To attain this theoretical ratio, I would need to add 10% of 88 mcg, or 8.8 mcg of T3. A dose of 1 grain of desiccated thyroid + 50 mcg levothyroxine equals 88 mcg T4 + 9 mcg T3, which is what I’m currently taking. While others may think this dose is far too low (only time will tell), other lab markers were telling me that higher doses were too much for me (the various types of medications and the problems I’ve encountered are covered in my book).

I know others who are also taking 1 grain of desiccated thyroid, but combining it with different amounts of levothyroxine, which happens to correlate with their weight. Here’s another example:

Male, 185 pounds = 84 kg

84 x 1.5 = 126 mcg T4

His current dose is 1 grain + 88 mcg T4, which is 125 mcg T4 + 9 mcg T3. This makes his T4:T3 ratio about 14:1 instead of 10:1, but I don’t know if all men have a higher ratio, or if everyone only needs about 1 grain as a base, and levothyroxine is what increases or decreases based on weight.

I am well aware that this formula will not work for everyone, but I thought it was an interesting way to calculate a reasonable dose for some people. We can’t dose by TSH, and reference ranges are so broad that widely different doses will give “normal” results. Of course, this formula doesn’t address any nutrient deficiencies such as low iron, cortisol, Vitamin D, etc. either, but at least it can be used as a base guideline by those who are undermedicated and on a dose that is far too low for them to function simply because their TSH is suppressed.

" tiredthyroid.com/blog/2014/...

so my weight is 78 kg x 1.5 = 117 mg of T4 ... I am still undecided if taking NDT +t4 or only NDT. I'v e read T4 combination could be tremendously beneficial to mimic the right human thyroid production.

any thoughts?



As the way a person "uses" their thyroid hormone replacement is so multifactorial & dependant on varying entities, I would say that to even "regressively" consider only .... [ ..age, sex, ideal body weight, body mass index, and body surface area .. ] ... is not enough. What about diet, other health issues, environment, stress issues, nutrient//iron//sex hormone deficiencies, genetic disposition, hair colour ? ! ? ! .. (lol) .... ).

A Levothyroxine dose is vaguely based on a person's weight (although the golden TSH takes precedence) but I would say your formula is flawed ... ;o))) ... We are all different and it is how you feel that counts .

What does all this have to do with what you should be dosing ? ? ... as my suggestion of your NDT was only based on your previous T3//T4//NDT meds ? ? ...

.. .... .[.... .A dose of 1 grain of desiccated thyroid + 50 mcg levothyroxine equals 88 mcg T4 + 9 mcg T3, which is what I’m currently taking .. While others may think this dose is far too low (only time will tell) .... . ] ... .. equivalent to 142mcg T4 & (I don't consider) not particularly low as I medicate 2.25 grains equivalent to 146.25 mcg T4. ( My thyroid gland is smaller than a weeny shrivelled pea.. I saw it last year on saliva gland scan.)

... You've written a book ? ? ... ;o)) .... .

Glad you are reading as knowledge is power... but remember ... [.. Imagination is more important than knowledge. For while knowledge defines all we currently know and understand, imagination points to all we might yet DISCOVER and create ... ] ... - Bertie E (AKA Albert Einstein).

Everything changes when we read and I love discussion. I would medicate NDT and retest in six weeks. If T3 is low, add some more. If T3 is high, reduce NDT & add T4 ... simple...

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Petfect! Thank you @@☺️

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You are very smart that's why I would like you to answer this question that nobody else has able to resolve please.

But first let me clarify this. You said 2.5 grains is the equivalent to 145.25mcg T4. However, a grain is around 38 mcg T4 and 9 mcg T3. So 2.5 grains are in reality only 95 mcg T4 aprox. Am I wrong?

Ok, my first question is in regarding the T3, but first let me elaborate:

For the first time in this year I reached a good level of T3 with my dose of T3 12.5 mcg + 1 grain which contain also 9 mcg T3 = 21.5mcg T3 that was reflected in my last Lab. (Not T4 obviously so I need more T4):

- 08/29/2016 1 grain NDT + T3 12.5 mg + T4 (levo) 50 mg = FT4= 0.9 0.8-1.8 ng/dL ; FT3= 3.5 2.3-4.2 pg/mL

I know the FT3 shows a 3.5 BUT because it was taken more than 24 hours, so in reality if it were taken 6-8 hrs it would reached around 4.1 or something which is the desired range everybody fights for. So if I take out my that 12.5 mcg T3 as you suggested just to avoid my shaking hands means and replace it with the 2.5 grains I would still get 22.5 mcg T3 contained in those 2.5 grains which is even 1 mcg even more of the dosage I was taking (1 grain + T4 50 mcg + 12.5 mcg T3)

Any thoughts then?

Thank you in advance



Thank you.

It is a muddle we can find ourselves in with our confused foggy brains ..... remember T3 is 3-4 times as powerful as T4.

It is true you need a guide of what med dose to take (otherwise we could end of taking a dangerously high//low amount) but you choose to place so much emphasise on other's exact amounts instead of finding your own.

You have swopped doses and changed meds so many times, (each probably bringing its own set of further problems) as these hormones take many months to reach their full potential. A full year after starting T3, I was still seeing improvements and after switching to NDT just two months ago, these continue. I have had a rocky road to tread just like everyone else but I stuck with it.

Results are only a paper copy of an indication. Sometimes biochemistry can tell a very different story to how we are feeling and it is a good idea to reduce the T3 if you have shakey hands but you must stay on a dose for several weeks//months to establishment the true benefits (or not). (Also shakey hands could be adrenal issues if you don't other hyper symptoms ? ? ..) ..

Manufacturers state that 1 grain is BIOACTIVELY equivalent to 100mcg T4 (NOT that it is equivalent to 100mcg). The actual T4 + T3 content in one grain is equivalent to 65mcg T4 if you use a 3:1 T3:T4 ratio, OR 75mcg if you use 4:1 ratio.

I say - 1 grain NDT : 38 T4 + 9 T3 (equiv 27 T4) = 65 mcg T4.

2 grains NDT = 130 mcg T4

2.25 grains NDT =146.25 mcg T4. (Note this is two and a quarter grains (my dose).

You only need one set of rules so choose a ratio & stick with it as alternating will complicate things.. The important thing is to monitor your symptoms and your vitals to make sure you are not over replacing (or experiencing further adrenal issues when not used to taking correct amount of T3).

I think I read the average amount of NDT medicated is 3 grains but I believe it important to take the least amount we can function on as have found the better I became, the better thyroid meds were utilised. Now, I function well on LOW in range thyroid hormone levels. Like many, I have MTHFR issues so any unused hormone is not excreted easily but builds with possible negative effects.

When medicated by my doctor I withheld meds before a thyroid blood test as to be seen with a too low TSH & high hormone might have led to a med reduction. However, now I self medicate, I have no need to stop meds before a test which can only serve to further stress our poor (already) stressed adrenals.

If you consider 2.5 grains NDT too much, start on 2 grains NDT. IT is difficult to assess your needs because of all your changes. I actually started on 2 grains too and it became evident very quickly that I was lacking. I added a quarter grain and waited ....it did not take me long to recover ... say 2 - 3 weeks. It is better to be slightly under replaced than over and for many their sweet spot is very slim..

If this were me I would start on two grains NDT, take temps and pulse every morning and retest after six weeks. Dose adjustments//other meds can be assessed after six weeks and will depend on test results and how you feel. You only need another med if the NDT is not filling your exact requirements.. (ie not enough T3 so you add some more, or too much T3 so you reduce NDT dose and add T4).

Good luck.


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