Thyroid UK

blood test results on NDT

My 26 year old daughter born without a thyroid (congenital hypothyroidism). She has recently had first blood tests on NDT (Nature-Throid) taking 4 tablets daily each tablet (1 Grain or 65mg; Daughter takes 1 tablet at 8am, 12pm, 4pm & 8pm. The Endo is not happy with the results can someone explain what they mean please & what she may be doing wrong with the dosing. However she is almost symptom free on this dose & is the best I've ever seen her. Previously on Levothyroxine & her life passed her by as she struggled to cope with more symptoms than I care to count!

TSH 40.84 - (0.30 to 4.50)

Free thyroxine 7.6 - (11.0 to 22.0)

Free T3 6.4 - (3.10 to 6.80)

Daughter had the appointment with Endo at 9am so she had taken 1 65mg tablet when bloods were taken.

Thankyou for any help

8 Replies

You mean she'd taken one grain just before these tests were done? I dread to think what they would be like if she had left 24 hours as you're supposed to!

Her endo isn't happy because her TSH is much much too high and her Frees much too low for someone on 4 grains of NDT. He might even accuse her of non-compliance - not taking her hormone. Does she always take her tablet on an empty stomach - one hour before food or any drink except water, or two hours after food and drink - and four hours away from suppléments and other medication? If she does, then I Don't think there's anything she's done wrong.

So, what do they mean? Well, they mean she's Under-medicated. Her TSH should be around 1 and her FT3 up near the top of the range. Her FT4 is bound to be low as she's taking NDT, but not that low.

I'm amazed she feels well with these results. Are you certain there couldn't have been some mistake with the lab? I think the endo will probably want to repeat them, because they just aren't logical.


Thank you for your reply greygoose.

She took 1 grain at 8am with water, no food & blood tests around 9.30am.

The thing is the Endo is saying her results are consistent with over replacement!

He states in his letter that on examination she appeared euthyroid, no palpable goitre, pulse 80bpm in sinus ryythm, blood pressure 120/80 without a postural drop & she had normal reflexes.

Her previous results 3 months earlier based on her taking 2 tablets (1 Grain) of Nature-Throid an hour before the blood tests were:

12/03/2015 - TSH 20.77- (0.30 to 4.50)

12/03/2015 - FT4 12.00 - (11.0 to 22.0)

12/03/2015 - FT3 11.5 - (3.10 to 6.80)

Again on these tests he said over replacement (at this time she was taking 2 in the morning & 2 in the evening).

I am very confused.


yes, i'm a bit confused, too. I Don't see how an FT3 of 6.4 shows she's over-dosed. But, the test is nul and void because she took her tablet just before the test. You should always leave 24 hours before the last dose and the test, otherwise, things like this happen. And if you can have it done before 9.0 am it's better. BUT all that doesn't explain the TSH...

Apart form anything else, these tests weren't designed for someone with no thyroid on NDT. They are meant for people taking Levo - T4 - only. I Don't understand the TSH, there's something wrong there. But then I Don't have any experience with people who are born without a thyroid. I don't know if that makes any difference, but you would expect it to be suppressed on 4 grains. That TSH says she's Under-medicated, not over.

But he cannot say on the one hand that she is 'euthyroid' and on the other she's 'over-replaced'. That just doesn't make sense.

Still, if she's feeling well on that dose, then Don't let him reduce it! Just refuse. And if he won't write the prescription for the dose she needs, then buy your own. The most important thing is that she feels well.


Well I have no medical qualifications whatsoever, but I'm not sure what relevance the TSH number has when there is no thyroid in the body. I am guessing that upsets the feedback loop which would notify the pituitary gland that there was sufficient t3 in the body.

I think the t3 results in particular are reflecting the fact she has taken medication within the previous 12-24 hours.

Perhaps you should go more on the symptoms rather than the numbers if your daughter is feeling good on this regime.


We are buying the NDT (Nature-Throid), the Endo won't prescribe it but he said he would monitor my daughter when she is on it as she has had a terrible time for 24 years on T4 (Levothyroxine). His aim however is to let her have some respite from T4 as she is now symptom free but he wants to convince her NDT is dangerous & he hopes she will re-consider going back on T4 in a couple of years. We are waiting for 24 hour ECG & Dexa Scan as he is convinced they will prove NDT is dangerous.

These results are scaring me as I will never forgive myself if anything happens to her as together we decided NDT was worth a try & it is me who buys it as she is only now well enough to look for a job & come off long term sick (sickness caused by the Levo). Guess that answers my own comments, the fact she is now capable of working instead of attempting suicide as she has done 3 times on T4, not having a life & losing her friends who don't understand, plus a ton of other symptoms.

I have made an appointment with the nurse for new thyroid tests & we will ensure that she takes no tablets for 24 hours before the tests, if they are normal or more normal I will be one happy Mother!

1 like

For many years the only treatment available for thyroid conditions was NDT, and many thousands of patients did very well on it. There were no blood tests then so a doctor would keep increasing the dose until someone was feeling hyper symptoms (fast pulse, sweating, loose bowels), then decrease the dose a bit. Doctors like to make people worried about NDT but only because they are discouraged from prescribing it and they like to be in control of their patients.

If your daughter is feeling well I wouldn't let the doctor mess things up by changing things.


Thank you eeng, you are correct & we will continue as we were with the NDT, it does worry you at first but then I just have to remember how sick she was on Levo & how the Drs didn't care she was sick as her TSH was OK. In my opinion a Dr is there to make you well not keep you sick!


I came off levo 12 weeks ago. And although still trying to get optimal on ndt, will not go back to Levo because I have put up with really bad stomuch pain every morning on levo for years, which the doctor treated with ppi's to block stomuch acid. Never mind that I need all my stomuch acid to digest food! That can definitely cause osteoporosis and various deficiencies due to bad absorption from reduced stomuch acid! On NDT, pain went away immediately, no more ppi's, what a pleasure. Good luck with ur daughter, I'm sure ur on the right track ;)


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