Thyroid UK
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Low T4 & TSH with chronic sinusitis & constipation

My endo said I have low T4 at 13 (it shouldn't be lower than 12 with their range.) But my TSH is 0.3. She put it down to me being on NDT (Thyroid-S) she said NDT has too much T3 & not enough T4? But I've been taking both Levo & NDT together so I don't think it's that. I tried being on both separately but that didn't work & I developed sinus problems & constipation. Now she's put me on T3 Lio with my Levo.

I can't figure out why my T4 won't get higher. I take vitamins, B, D, iron, eat fruit & veg. Could it be my body just can't absorb T4 but then why is my TSH low?

6 Replies

I've just learned on here it could be cos I was taking too much T3 from the NDT. Can't wait to see if Lio intake will increase my T4 as it's a lower dose than NDT. So much fun.

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How much T4 and how much T3? I very much doubt you were taking too much T3 when taking NDT. And you would only have know if it was too much by testing the FT3. Nothing to do with the FT4. But, any amount of T3 will mean that your body doesn't hang on to as much T4, so your FT4 is always going to be low. But, doctors have no idea about treating with NDT.

Taking 'lio' is not going to raise your FT4 if you're taking a decent dose. But the FT4 is unimportant when you're taking any form of T3, anyway. The only important number is the FT3.


Your Endo only knows about the effects of levothyroxine - she wont know about NDT except rumours.

Before levo was introduced and before the blood tests too, we were given NDT which was gradually increased until our symptoms resolved.

NDT contains T4, T3, T2, T1 and calcitonin. Levo only T4 - so the blood tests cannot equate to being on NDT. Also if T3 was added to T4 (levo) our T4 will be lower due to the taking T3.

Your Endocrinologist knows little about NDT and this is what I believe is the best way to treat patients after an initial diagnosis.

NDT should be increased every 2 weeks until symptoms are relieved, taking note of pulse/temp.

For information only and I'm not medically qualified. I have hypo but am well now.


Hi Shaws,

Can I please ask how you got well whilst hypo? Which meds/supplements do you take?

kind regards



Hi I take 2 grains of NDT Thyroid S only and feel great. Temp normal. Going to the loo ok and' slim again. I still feel a little tired at times but that's all.

Why are you mixing these together. When I was on 3 grains per day I had over the range FT3 also going to the loo too often so I gradually reduced down to two. My TSh is 0.08.

I don't bother with the doctor I just do my own thing now. I still go to the Endo and pick up my prescription for 100 mg Levo but I don't take any, ever. On levo I felt very ill, had constipation and aching bones etc also very low temp. By the way I have no thyroid.


When I switched to NDT (Thyroid-S 120mg) alone I developed chronic sinus problems (and I already have breathing problems) so that's why I went back to the mix. I'm giving the Levo/Lio a go, plus I don't eat meat so didn't feel comfy taking pig gland. I still think the cysts in my thyroid may be causing this but every doctor (including American & Italian) has said cysts don't affect thyroid function. Have there been studies on thyroid cyst effects I wonder?


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