Thyroid UK
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New blood test, same dose, worse fT3


I've just received another blood result. I had a blood test 2-3 weeks after the previous one to confirm the results I had gotten, whichI had found weird. Now, as I thought, fT3 appears to be much lower than in the previous test. I didn't change anything between both tests (taking 75mcg T4 and 15mcg T3, Novothyral), and did both 24 hours after last dose, with empty stomach at the same place. I think the previous one was just an error, isn't it?

3 weeks ago (posted before):

fT4 0,67 (0,90-1,90)

fT3 3,3 (2,5-3,9)

TSH not measured (always very low, secondary hypothyroidism)


fT4 0,67 (0,90-1,90)

fT3 2,6 (2,5-3,9)

Both fT4 and fT3 are now very low (I had never had such a low fT4), and this is closer to the truth: this is the fT3 result I usually have, and I have been feeling VERY tired and slow the last couple of weeks. Worse than I felt when I was taking T4 alone (my highest dose was 150mgc T4, which gave me palpitations but left T3 below normal...)

I wanted to increase T3 by taking it separately (that's why I've been looking for information on Cynomel and Triyotex...), as I have taken Novothyral 100mcg/20mcg before and it seemed to be too much, but now I am not sure if I shouldn't try to raise fT4 as well... What do you think?

Thank you for your opinions!

2 Replies

Miriammsm, I think you're undermedicated and Novothyral 100 (100mcg T4 + 20mcg T3) may be a more appropriate dose.


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.


Thank you Clutter. Yes, I think I will try to take Novothyral 100/20 before doing anything else, but that's actually what I did for a long time last year. The effect was high-normal fT4 and low fT3. I felt it was almost too much T4 (palpitations, too warm, a little anxiety), but at the same time my metabolism (apart from temperature) was still low, probably because of T3.

Then I decreased t3 and kept T4 at 100/10: the result was still normal-high t4 but too little t3, which was even lower. Now I was trying to decrease t4 to be able to increase t3 above 20, but never thought t4 would decrease so much by dropping to 75 mcg t4...

Let's see.

Thank you again!


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