Thyroid UK
82,694 members97,731 posts

Help with blood test results

Hi wd be grateful fr feedback/advice on recent blood results done 6 wks after increasing meds to 75mcg T4 + 25mcg T3 - previous dose 50mcg T4+20 T3.


TSH <0.03. (0.34-5.6)

T4 13.2. (7.5-21.1)

T3. 5.4. (3.8-6.8)

Ferritin 51

Serum cortisol 318 (198-700) 8.30am fasting.

Adrenal saliva test showed low morning cortisol

On previous lower dose( 50T4+20T3) rslts were:

TSH 0.03 FT4 7.9 FT3 4.9

In spite of being v tired on this dose Endo wanted to reduce meds as TSH suppressed.

GP refused to continue to prescribe T3 and I decided to buy T3 and self medicate.

I am still tired on the increased dose and wondering of I shd increase meds and if so which one and by how much.

Before starting combo on T4 100

My Results were TSH 0.03 FT4 16.2 FT3 4.8

So again TSH suppressed.

I queried a pituitary problem and Endo suggested I stop meds for 2 wks to see if TSH wd rise.

As it went to 5.86 with FT4 at 4.6 and FT3 3.2 I was advised that I did not have a pituitary problem. From reading other posts it seems that other members have had blood test and scans to check out their pituitary function. Just wondered if this needs further investigation.

4 Replies

Caze, As your TSH rose when you were off meds it doesn't appear you have a pituitary problem. Your TSH responds very well to medication and I don't see that should be a problem or require a reduction in meds as neither your FT4 or FT3 are elevated. Your FT3 has room for improvement as it isn't yet in the 'ideal' top 75% of range or >6.05.

I'd increase your T3 by 1/2 a tablet to 37.5mcg and see whether that improves your tiredness. You may want to split the dose to take 25mcg in the morning and the remainder 4/8 hours later.

Low ferritin, vitaminD, B12 and folate also cause fatigue. Your ferritin is below the optimal level of 70-90 and will be improved by supplementing ferrous fumarate. Take each dose with 500mg-1,000mg vitamin C to aid absorption and mitigate constipation

I can't help with cortisol.


Thks Clutter

My ferritin was only 25 before I started supplementing so there has been an improvement but levels still need to come up a bit. Low iron can cause tiredness so this cd be part of the problem.

Looking at my TFT I did think I cd raise meds but was thking of both T3 and T4 by just a little as both levels are on the low side, especially the T4. U did not mention raising T4 only the T3 - just wondered why - is this not so important if u r on a combo? I seem to recall reading somewhere that u shd aim to get yr levels towards the top end but not sure if this applies to both T3 and T4 if u r taking both.


Caze, taking oral T3 bypasses the need for so much T4 storage/conversion so T4 is often lower than the 'ideal' 75% of range aimed for when on T4 monotherapy.

When on combi you don't raise T4 & T3 simultaneously, iust one or the other at a time. I suggested raising your T3 because your FT3 is a little low and because T3 improvement will be faster than increasing T4.


Many Thks will give it a try.


You may also like...