Is T3/T4 suitable for TSH Supression?

[MrsBrass]

Hello - I had stage II Follicular Cancer with lymph node spread and following TT and RAI my thyroglobulin is zero and my TSH is suppressed. I have lingering symptoms and whilst my T4 is always at the top or out of range, my T3 is always at the bottom of the range (regardless of my T4) .

I'm going to ask about trying a T4/T3 combination but I dont know if this is an option following cancer if TSH needs to stay suppressed. Can someone advise if I were to take a T4/T3 combination, would my TSH suppression be affected, or will it have no impact

Thank you

[Dr Petros Perros]

Dear Mrs Brass

T3 is less good at suppressing the serum TSH than T4, but it is possible to achieve TSH suppression, with a T3/T4 combination. I have never been convinced that the combination treatment is better than T4 alone. I doubt that your symptoms will improve with T3, but it is sensible to discuss this with the doctor who is supervising your treatment. He /she will need to look at your results and judge whether the T3 is too low and if so whether there is an underlying cause. If you jointly decide that it is worth exploring whether raising the T3 makes a difference to your symptoms, then that could be achieved either by increasing the dose of T4 or by adding T3.