TSH 0.01. On NDT - been advised I'm over treated . If I get pregnant and TSH remains low what can I expect from the GP

Hello all.

I'm on NDT and TSH now 0.01, T4 13.5 T3 5.6. GP has commented I'm "over treated with thyroxine" He had advised a decrease but Doctor P advised an increase to get a brighter T4 which it now is . (TSH was 0.05 before) Can you help me out as I'm now going to have to explain the suppressed TSH. I've had a good run with no discussions but it's come to an end .

Wondering also if I get pregnant what will happen with this suppressed TSH - what will be acceptable to the GP ( maybe they will pressure me to increase) I definitely won't want to switch from NDT .

Doctor P is in hospital at the moment .😟 I have a consultation booked next week and I'm worried I might lose his support and be left floundering .


14 Replies


Being hypothyroid and being under treated can cause infertility and miscarriages. Being hypothyroid and under treated and you manage to get pregnant and stay the course the baby is likely to be born mentally retarded (cretinism).

It depends on the range of course, but those figures to me seem to be perfect, as you are on NDT. In fact just where they should be. How are you feeling. Depending on the range of course but your T3 looks fine if the top of the range is 6. It also depends when you last took your NDT before the test. When on NDT the TSH is a useless test. If you took your NDT within say 12 hours of the test it might be showing artificially high.

The TSH comes from the pituitary. If the pituitary is working properly if it detects there is insufficient thyroid hormones it sends out TSH (thyroid stimulating hormone). However when taking NDT there is all the thyroid hormones there so the pituitary, if working properly, detects that there is no need to stimulate the thyroid into producing more hormones because you are getting all the hormones, hence the TSH being very low or suppressed. So the important tests are the T4 and T3. As the active hormone is T3 then that is the most important. T4 has to convert to T3 so therefore if only doing the T4 this takes for granted that you convert OK.

I am not medically trained so the above is just what I have gleaned from reading and the experiences of family and friends. If the doctors advise something against what you consider to be right, ask them to put their reasons in writing. They are more cautious when asked to put it in writing in case something should go wrong and you have the evidence which they cannot lose or deny.

Took NDT 24 hours prior .

I think they're perfect too.

I like the put in writing advice : thanks

Go by how you feel not numbers.

Are your FT4 and FT3 in range? My TSH has been <0.01 for the past ten years, and I am very much alive and doing well:-) For me, FT3 seems to be the most important hormone, and it determines how I feel. The TSH has never correlated with how I feel. When I had a so called normal TSH, between 1 and 2, while on thyroxine only, I felt lousy, kept gaining weight, was constantly tired and honestly could not understand why my doctor at the time called thyroxine a "wonder drug"...

I have also noticed that when my TSH is suppressed, my antibody levels go down.

Yes - that's what I'm doing - I feel great but my concern is how I will be proceeded with in the GP setting if I get pregnant ( which is the plan) I just wondered if anyone had any helpful experience /research about suppressed TSH and pregnancy . I want to be one step ahead ! I have done a bit of research already .

That's a very good question; if a drug-induced suppressed TSH is interpreted as hyperthyroidism by the body, will that make it more difficult to get pregnant...? You often read that a high TSH (hypothyroidism) will make it more difficult to get pregnant, but what about hyperthyroidism...? And is a suppressed TSH really the same as hyperthyroidism, as long as your free Ts are in range? Hopefully, someone here will know.

But this is not hyperthyroidism because although TSH is suppressed the T4 and T3 are in range. If it were hyper then the T4 and T3 would be above range. Same as it is still hypo if T4 and/or T3 below range even if TSH is within range as mine was. My T4 was right at bottom of range and my T3 was below range (I was so ill) yet my TSH was 1.6

This link should help, as doctors can miss adrenal fatigue either as primary or secondary to hypothyroidism... If your having what seems like relapses IE if your ok for a few months then relapse and need to increase your thyroid meds. This can indicate adrenal issues, read this link hope it helps...


I don't think the lack of thyroid production is interpreted as hyperthyroidism by anything but rather stupid doctors. Your TSH is low because there is enough thyroid hormone in your system, and therefore no need to make more.

Also T3 dosing, either via NDT or synthetic T3 (liothyronine) is known to suppress TSH production.

Assuming your ranges are similar to mine your T4 is low in the range and T3 is a little over half way up the range and you could safely increase (but only do that if you don't feel great).

I think hypothyroidism causes conception problems not because TSH is high but because the whole system tends to become sluggish, and that probably means that the complex hormone synchronisation needed to get an egg released, fertilised and then implanted in the womb at exactly the right stage of development is disrupted. As far as I am aware there is no research to suggest that TSH level directly affects the reproductive system. My guess is that it is more that T3 affects every cell of the body, and not enough causes problems, as we know.

If you were indeed hyperthyroid then things might get unbalanced as well, although I haven't heard of it causing fertility problems. But you aren't. Your FT3 level is pretty well perfect.

Exactly ! Well said . My anxieties lie with incompetence and scaremongering .

This is worth reading :


This post is relevant to your question, hope it helps... N maybe print n show your doctor


Thanks- I appreciate that. I have that one in my folder. I've got some great studies and other stuff to take .

Will probably update on here ...

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