When will I feel the effects after t3/t4 combo ... - Thyroid UK

Thyroid UK

113,044 members131,359 posts

When will I feel the effects after t3/t4 combo medication?


2 years diagnosed under active thyroid - Hashimotos diagnosed a month ago Peroxidase level of 1019 . increased T4 to 200 mcg Thyroxine with no positive effects then saw an Endo last week and he has changed my dosage to 150mcg Thyroxine 10mcg Liothyronine I have been on this for 5 days with no changes despite being told I would notice in a couple of days?

Up until 2 weeks ago my TSH was always 6.39 now it is 1.29

Any advice please still very Hypo , can hardly function ! I look so tired my friends and family have started mentioning it! 33 years old 90kg

15 Replies


I am sorry you are still feeling unwell. It may take a little while for you to feel better. Some people feel the benefit of T3 quickly and for others it takes some time. The ratio of T3 to T4 may not be high enough yet. I was given 10mcg of T3 to 50mcg of levo. I had been on 75mcg levo alone previously.

Do you have your FT4 and FT3 blood results?

FT3 is particularly important, because this will indicate if you have a T4 to T3 conversion problem, which could explain why you did not feel better on such a high dose of T4.

When I started taking T3. I found that neither 5mcg or 10mcg had any effect. 20mcg T3 was the minimum dose that made any difference for me.

You should notice the initial effects of taking T3 in around 2 days up to 2 weeks.

The effect of reducing T4 takes 4 - 6 weeks.

FT4 15.9 up from 13.2 2 months prior (range 9-24) No FT3 at all on any tests?

I recorded from her reading out:

cortisol 226

B12 382

Glucose 5.1

liver alkaline phosphorus 81

ALT 21

Ferratin 111

corrected calcium 2.47

It seems odd to prescribe T3 without knowing the FT3 level, especially as T3 is the active thyroid hormone.

Sound to me like you should insist on having your FT3 checked, as this is so important to finding the right T4 and T3 medication for you.

Finally got new labs with t3 level!

Tsh 0.06

Ft3 4.7 (3.9 - 6)

I can only guess my ft4 is same at 15.9 ( 9-24) they didn't test it although requested!

He just increased my 20 t3 to 30 and sent me away again!

Any thoughts?

I too was diagnosed with Hashimotos in 2005. I started on 25mcg of T4 and found it difficult to increase dose. Eventually raised to 50/75.... I then added T3 to the mix - and felt unwell. Under the guidance of Dr P I reduced T4 and went T3 only. That is where I have been for the last couple of years and feeling fine.

I would mention though that I have also started high doses of VitD and attended to Ferritin - Folate - Iron - B12 levels. They all need to be high in their ranges for you to feel well and for good conversion of T4 into T3. It seems to me - that Hashimotos people have more problems with conversion - only a feeling - no evidence.


Also need to mention gut issues - often Hashimotos is linked to inflammation in the gut. As with other auto-immune conditions. I have Crohns diagnosed over 40 years ago .....

When I was on 175 of T4 and my endo put me on the combo, I was given 100 of T4 and 20 of T3. I began to notice a change within a few days, but I would give it a bit longer. However I think the ratio of T4/T3 you have been given should be different and you might benefit from more T3.

do I have to always decrease t4 by 50mcg for every 10mch T3 added? I understand that t3 only lasts 8 hours max so can I add another 10 after 8 hours without decreasing T4 then? its a bit confusing?

Given your test results, I think decreasing your T4 was a mistake. Your t4 is quite low in range. As your T4 was reduced you would need significantly more t3 than 10mcg.

I believe you need more t3 and/or t4 and that you are currently under-replaced on your current treatment. Of course, I am not medically trained.

Carolyn x

Finally got new labs with t3 level!

Tsh 0.06

Ft3 4.7 (3.9 - 6)

I can only guess my ft4 is same at 15.9 ( 9-24) they didn't test it although requested!

He just increased my 20 t3 to 30 and sent me away again!

Any thoughts?

It's a good start. Hopefully you will notice some improvement. It's good that he is going by your t3 rather than your TSH. Hopefully he will continue to ignore TSH in favour of t4 and t3 and how you feel.


Do I really need all that t4 though if it's just a storage hormone ?

Would it matter if I reduced it?

If my ft3 is only 0.7 off the baseline it must have been awful before the addition of t3 ! Which must indicate that I'm not converting , I have been all the way up to 200 t4 with no positive signs/ symptoms ?

It's driving me mad feeling and looking tired all the time and I just want to find what my sweet spot is ! 10mcg increases every 2 months could take years to solve! Lol

Well, I am on T3 only. I don't seem to be able to tolerate t4 at the moment.

If you can convert, it is useful to have some t4 for when you're body needs some extra. However, if your body can't use it, there is little point.

10mcg every 2 weeks is a bit slow. Every month would probably be fine until you get near to your optional dose.

Let's hope it doesn't take too long to get there!

Because my tsh came back at 1.29 the lab didn't bother with the t3 it was on the blood form because I took a photo of it !

You may also like...