Thyroid UK
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Confused with blood results, any idea how to proceed

Hi everyone. I have been self medicating lately and it seems that I have done something wrong so I hope somebody could help..

My GP was never of any help so my first blood test was done privately. I had many symptoms like most of the thyroid sufferers. My first blood results before the medication:


TSH 1.50 (0.27-4,20)

T 3 1.06 (1.30 – 3.10)

F T3 3,75 (3.10 – 6,8)

F T4 18.1 (12 – 22)

Anti Tpo 600 (0-34) Anti tg 24 (0-115)

My endo put me firstly on 25 mcg (6 weeks) and then to 50 mcg of T4. Some symptoms have gone, but some did not, especially low temperature and some slight joint and muscle pain.


TSH 0.71 , FT4 21.8 (12-22) FT3 4.10 (3.1 – 6.8) Tpo 45 (the same ref)


TSH 0.50, FT4 18.2, FT3 4,02 Tpo 32 RevT3 444

Ferritin 150, B12 930 (both high in the ref.r).

As I was constantly feeling cold and thinking that I do not convert well (high rt3), I decided to try T3 only, taking for a 2 month period, and no t4.

I was taking total of 15 mcg t3 in three daily doses, and the blood results were as follows:

TSH 1.68 FT3 4.95 FT4 12 (the same ref).

So I guessed (because the tsh went up and t4 fell) that I needed back some t4.

So I went back gradually to a combo therapy, 37 t4 and 6 t3. I must say I have being feeling good, the temperature was/is a little better (35.5 am and 36.4 pm), although some slight brain fog has come back. But, after 5 weeks, the results came as a surprise:

FT3 2.43 (3.1-6.8) , FT4 19.2 (12-22), TSH 0.40, TPO almost non existent.

How come the ft3 was better on 50 mcg t4 only, then on the combo t4/t3 37/6 mcg??

I am somehow confused. Did I make a mistake switching from t4 to t3 and the combo???

Should I go back to t4. I have also noticed that some of the symptoms of the low t3 have come back, eg irritability and brainfog.

Thanks for any advice.

10 Replies


Your joint and muscle pain may be due to low vitamin D. It's worth having vitD tested.

It's not uncommon for FT4 to drop when T3 is added. Taking oral T3 means there isn't the need for higher levels of T4 to convert to T3. FT4 and FT3 levels don't respond to meds as quickly as TSH. Your levels may have dropped if you'd stayed on 50mcg T4. The 45mcg T3 you were taking is equivalent to 135mcg T4 so you gave yourself quite an increase.

I'd be inclined to raise your T3 to 18.25mcg (3/4 of a tablet) to improve your FT3 which should improve irritability and brain fog and continue on 37.5mcg T4 and retest again in 8 weeks.

Medication has been very good in reducing your Hashi flares and antibodies.


Clutter, Thank you for the reply. It was not 45 mcg t3 that I started my t3 only therapy with.

It was 15 mcg t3 in total in three Daily doses (6+6+3 mcg).

What surprised me was the fact that my ft3 on 50 mcg T4 was much better than on combination 37 t4+6 t3. I do not understand this. Do you have any explanation?

I have just finished reading the book by dr. Blanchard "The Functional approach to hypo.."

His ideal ratio of t4/t3 is 98.5/1.5. He thinks that too much t3 will certainly supress TSH. According to him, TSH is a stimulator of the peripheral Type-1 deiodinase enzyme in tissues.

So we come to a paradoxical situation: the more oral t3 you take, the more supressed TSH you get and less t3 you get in the body by its own conversion of t4 to t3. The paradox goes on with his statement "In the patients who come to my practice who have taken t4 in the past, the almost universal mistake made in their treatment was to give too much T3. Since T3 is said to be the direct acting hormone, the natural instinct of the doctor, when fatigue is back, is increasing the amount of t3. However, my experience is that the way to adjust over time is a gradual increase of the T4/t3 ratio, which means raising T4 (if the TSH is not too low already) or reducing T3.


Akimbo, I misread it. 15mcg T3 is equivalent to 45mcg T4. As I said, FT3 may have been falling while you were on 50mcg T4.

I'm not sure about 'ideal' ratio's T4 to T3. They suit some, but by no means everyone. 37mcg T4 + 6 mcg T3 clearly isn't enough for you because your FT3 has dropped so low. If you increase your T3 it will improve. Alternatively raise your T4 to 50mcg plus 6mcg T3 but it will take longer. Whatever you decide you should try to stick with it for 8 weeks else your levels will be yo-yo-ing and you will feel unwell.


Thanks Clutter. I am confused with my ft3 levels. It seems that I am better in dealing with t4 supplements than with t3. Maybe dr Blanchard is right. Try first with t4 adding later just a very small amount of t3 and let the body do the rest. Well, at least in my case.


Akimbo, most people do well on T4 monotherapy. The others find T3 beneficial usually only after months/years of not being well on T4 when they find their FT3 levels are low.


But akimbohr, your body wasn't doing the rest. You weren't converting. Don't get too hung up on what just one Dr says. Read a selection of books and get an over-all view, get a better sense of how things work and what are the obsessions of various doctors. And bear in mind that what works for one, won't necessarily work for someone else. We're all different.

It would also be a good idea to get some vits and mins tested. If your B12 is low you will have lots of symptoms. If your iron is low, you won't be able to convert.

Hugs, Grey


Do you mean that you were taking 15mcg T3 in 3 lots of 5mcg or that you were taking 15mcg 3 times a day?

If you were taking only 15 in total, you lowered your meds to about 45mg T4 equivalent.

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Hi Angel,

I was on the total 15 mcg t3 (6 mcg am+6 mcg noon+3 mcg pm). No t4.

My ft3 went up from 4 to 5 but ft4 went down from 20 to 12. Interestingly enough TSH also went up from 0.7 to 1.65 as if asking for more (ft 4 ??)

When I switched to combo 37 ft4 + 6 mcg t3 my ft3 was very low at 2,43, my ft4 normal at 19,

TSH also low at 0,40.

I was confused about that low ft3. How come ft3 is lower on combo t4/t3 than when I was on 50 mcg t4 only earlier in spring (ft3 at 4).

Either conversion problem or some underlying condition (inflamation, infection, autoimunity) which i try to discover which makes this low ft3 and high rt3. /ratio in june was only 8,5/

AT least my anti tpos on GF diet and medications are almost non existent any more.


Well, your TSH would go up since you dropped your total meds - but at least that means that your pituitary is working. You probably needed more thyroid hormone in total, not less, so probably should have added a small dose of T3 to the existing 50 T4, and raised the T3 gradually as necessary.

Did you check B12, ferritin, folate etc? All needed to convert T4 to T3.


B12 over the top, ferritin high at 150. I did not chech folate or vit D. I am taking b complex and have been enjoying the Mediterranen sun for a few weeks, so maybe it helped, but I plan to do the vit d test.

I had samo inflamations in the past, urino and astma and am taking some corticosteroids, maybe this is the reason of poor conversion. Or maybe some gut infections..I had them many in the past.

I think I must find the reason for the poor conversion. I guess it is some inflamation in the gut.

I still can't understand how come my ft3 was better on t4 than on t4/t3 combo.

My ft4 is at best when on 30 mcg t4 and my t3 is at best when on 15 mcg t3.

Do you think that taking this combo would take me to my sweet spot?


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