Log in
Thyroid UK
93,374 members107,425 posts

T3 thyroxine / naturethroid

Hi I have a question regarding thyroid medication ! I have been taking 100 mg thyroxine and 3 grains of naturethroid for quite a number of years and have felt fine on this dose .. I cannot lose weight and My endo decided to try me on 125mg thyroxine and 10 mg t3 split into 2 doses during the day, to see if this would help me . I tried this for 2 months and I started to experience feeling tired and felt like I was pushing a tractor up a hill energy wise ! I had blood test and my t4 had dropped and my t3 was 5.1 . She said she changed meds so as she could see directly how much t3 I was actually getting as with the NDT she said wasn't exact measurements ! What I'm trying to say is I felt a lot better on the NDT and not on the t3/thyroxine combination. And I still haven't lost weight 🙄

Has anybody got any advice for me as to why I feel worse on the thyroxine/t3 combination ?

Thanks in advance

7 Replies

Janey130 If you felt better on the Levo/Naturethroid combo, ask to go back on it.

Do you have any test results from when you were on this combo? It could be that you weren't on enough and you need an optimal level of medication for symptoms to disappear, and weight loss to occur. Also are all your vitamins and minerals at their optimal levels for thyroid hormone to work properly.

As far as I am aware, it's quite clear how much T4 and T3 is contained in NDT and doesn't Naturethroid contain 38 mcg of T4 and 9 mcg of T3 per 1 grain tablet.



Your endo has considerably reduced your dose and this may be why you feel worse on Thyroxine (T4) +T3 combination.

100mcg T4 + 3 grains NDT is equivalent to 325mcg T4.

125mcg T4 + 20mcg T3 is equivalent to 155mcg T4.

Apart from the dose disparity some people feel better on NDT rather than on synthetic T4+T3 combination.

There is 9mcg T3 + 38mcg T4 in one grain NDT so I'm not sure why your endo had difficulty establishing that you were taking 27mcg T3 via 3 grains.

Edited: 225mcg T4 should read 325mcg T4 and 185mcg should read 155mcg Janey130 and greygoose


I am not a medical professional and this information is not intended to be a substitute for medical guidance from your own doctor. Please check with your personal physician before applying any of these suggestions.


Well, actually, the endo put her on 10 mcg T3, so that's an even bigger drop in dose! No mystery to me why you feel worse, Janey130.


Hi thanks when I said 10 mg T3 split into 2 doses I meant 5 am and 5 pm so I'm presuming that's even less ?



It's 10mcg in total which I eventually calculated properly when I edited my post above.

1 like

Thanks Clutter appreciate your quick response ... So can you actually go above range when supplementing t3 . Do I supplement to how I'm feeling rather than blood test results ? I do feel much better back on NDT 😉



FT3 should remain within range whether you are taking T3 or NDT.


You may also like...