Thyroid UK
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Thinking of changing from NDT to Levo. and T3


Can anyone please advise me how I would go about changing from NDT to Levo. and T3 combination.

I have been taking NDT for six months and have only managed to work up to 1.5 grains. With every increase I have had to reduce again because of side effects. I did manage to get to 2 grains but experience a sudden rush of heat sensation throughout my whole body along with severe pricking and itching.

My blood results on 1.5 grains of NDT are,

TSH 0.42 range 0.35 - 4.7

T4 7.6 range 7.8 - 21.0

T3 5.2 range 3.8 - 6.0

I took my last dose of NDT 17 hours before blood was taken.

I felt O.Kish on this dose but there was room for improvement so I have recently added 12.5mcg. of levo. to bring my T4 up but do not feel any better.

Before NDT I was taking 125mcg. levo. but Doctor reduced to 100mcg. because of low TSH. I felt worse and went back to see her but she would not increase my dose back to 125mcg. but wrote to an endo. for advice. The reply was if I felt better on the 125mcg. levo. the I could go back on it as long as my T4 did not go over 18.

On levo. my T4 and T3 have usually been mid range but on the couple of occasions the T4 reached 19 and this is when I felt my best, my T3 rose slightly. This has lead me to think that a dose 125mcg. levo. and a small amount of T3 would be right for me.

Before the endo. replied I had starting NDT as I was so fed up of having my levo. reduced and thought I would give it a good go and really had high hopes for it. I have come to the conclusion that the ratio in NDT is not right for me and would like to go back on levo. and add T3 to it in hope I can get the combination right.

Before starting NDT and when taking 100mcg. levo. I did the Genova 24 hour urine test and it did show I was converting the T4 in levo. to T3 but I was just not taking enough of it.

Could anyone please offer any advice.

Many thanks lucylocks.

5 Replies

Im not the expert but....

You felt best on 125mcg levo. Take that again.

Get your hands on it however you can. We have to be resourceful.


I can get it now from my Doctor, she said I could go back on that dose after speaking to the endo. but I am not sure how I go about the change over. I am just so worried about changing back to levo. or levo. and T3 from the NDT in case I feel bad for a while.



You look to be optimally medicated on 1.5 grains NDT. FT4 is often low when taking NDT but that isn't important as your FT3 is good.

1.5 grains has 57mcg T4 + 13.5mcg T3 which is equivalent to 97.5mcg T4. If you go back to 100mg Levothyroxine + T3 your TSH will probably be suppressed and you may have the same problem of your GP adjusting dose according to TSH.


My G.P. wrote to an endo. for advice and he replied that he was not worried about a low TSH as long as my T4 did not go above 18. (not sure his reasoning for that) but I felt good with T4 at 19 (surely they cannot quibble about one point) anyway Doctor seemed quite happy with that.

1 like


It seems arbitrary of the endo to say FT4 should be <18 when the range is up to 21.0. Dr. Toft comments in Treatment Options that some patients need TSH suppressed with FT4 over range to feel well.

I felt dreadful with high FT4 (over range).


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