Thyroid UK
87,636 members102,331 posts

Blood test results while on T4/T3 combo

I've been taking 150mcg T4 and 40mcg T3 for the last few months and feeling much better. (previously on T4 only for 2 1/2 years since TT). My latest blood test required TSH, FT4 and T3. I phoned the surgery yesterday to get the results and as usual the receptionist refused to give the figures to me, then said it says I have to see the doctor for a routine appointment. I pressed her for the figures but she said she wasn't allowed to give them to me! So I made an appointment to see my GP next Monday.

I am pondering what the results might show and what my GP might try to do to my medication. I had heard that the blood tests are a waste of time if you are taking T3, but what about if you are taking a combination of T4/T3? Can anyone advise please? I know that my TSH was suppressed (0.0something on previous tests when I was just on T4).

Does anyone have any tips, so that I can be pre-armed with info just in case my GP gets difficult.


3 Replies

I am glad you are feeling better on the T4/T3 regime.

I am not sure why your GP wants to see you but you should definitely have a suppressed TSH if you have had a TT. What your GP may be concerned about is if your T4 is low but when you add T3 to T4, you will have a low T4, so if you are feeling well do not let him reduce your meds as that can upset your metabolism.

Just for you info, this is an extract from Dr Toft but it is not regarding T4/T3 meds but T4 only:-

In the past it has been customary to make sure that serum TSH concentrations are undetectable by using doses of levothyroxine of 125-200µg or more daily, depending upon the patient’s weight.

There is no good evidence that a suppressed serum TSH concentration – in the presence of an unequivocally normal serum total tri-iodothyronine – is a risk factor for atrial fibrillation or osteoporosis.

But the clinical consensus is that serum TSH concentrations in such patients should be low but detectable at 0.1-0.2mU/l.when you have had TT.


This is a link from Dr Lowe's archive site:-

Maybe someone will reply who has had a TT and is on T3/t4 combo.


Hi A a side issue, I have a print out from the receptionist, she checks with the gp before giving it me. That is quite normal and my practice is very awkward,so give it a try. make sure TSH, T4 and Free T3 have been tested.



Thanks for that info Shaws. It's very useful. I got my results, my GP gave me a print out and as she is a bit baffled, has written to my consultant for further advice on what to do. (although I am much improved on the T3, I get tired in the evenings still and there is definitely room for improvement). Yes my TSH was suppressed as expected at 0.01 and FT4 12.5(9.0-20.0) and FT3 4.6 (2.5-5.7). From what I have read those figures are not too bad and it will be interesting to hear what the consultant says when he writes back to my GP.

Jackie, thanks for that tip. Now I have had a print out from the GP I will be writing to the practice to ask for the print out next time to be issued by the receptionist.


You may also like...