Thyroid UK
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Low T4 and high T3 but feel good

I have Hashimotos. I have been on Liothyronine for about 2 months now and feel great (I had to have a slight tweeking to my Meds following a side effect on T3). I am taking the follow medication:

Levothyroxine 25mcg with Liothyronine 25 mcg in the morning and Levothyroxine 25 mcg in the evening one day, then Liothyronine 25 mcg in the morning (no Levothyroxine) and Levothyroxine 25 mcg in the evening the next day and so on alternating eachieve day.

My results from this are:

T4 = 7.2 (12 - 22)

TSH = 0.50 (0.30 - 4.2)

T3 = 8 (3.1 - 6.8)

Serum Cortisol = 273 (171 - 536)

My question is, even though the T4 is so low, why do I feel so well? Before I was prescribed Liothyronine I felt awful but my T4 and T3 were in "normal" range.

8 Replies

...because you are taking T3 :-) Well done too on remembering a seemingly complicated regime of T4 and T3 ....

If you start to over heat or have an increased pulse you may need to reduce the T3 a little .....

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T4 (and even T3 to an extent) can show good biochemistry even when we feel symptomatic. This is because the tests are measures of the hormone amount circulating in the blood and not the amount of intracellular activity (amount actually being used by the body in a positive way.)

T4 is often low when T3 meds are added and it is the T3 result that should be most considered. Your over range result shows you are over medicating T3 and this should be reduced.

We sometimes need to adapt the way we take our meds but your method appears a little complicated with no benefits. Splitting T4 into two doses a day is not any more beneficial because it is long acting, taking 7/10 days to be ready for conversion. Therefore you won't experience the spikes or slumps associated with the fast absorption of T3. You can medicate T4 & T3 together am or pm.

You are on a small dose of T4 and raising with a little added T3 will help conversion and so the total amount of T3 should equate to more than you medicate.

I would reduce T3 to 12.5 (1/2 of a pill). Many have to split T3 doses into two so 1/4 pill twice a day. Increase T4 to 75mcg a day. However, if that is too big a dose reduction of T3 you could try T3 18.75 (3/4 of a pill) and T4 50mcg a day. Either will give you the same total of thyroid hormone as you were previously medicating but in a better ratio that will reduce T3 but hopefully give you enough to continue feeling well.

Optimal iron, nutrients and cortisol with promote better usage and conversion of thyroid replacement hormone. Blood test thyroid hormones in six weeks to see what is going on.

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Radd, from my reading I gather that once you are on T3, and especially multi dosing, it is virtually impossible to obtain a correct reading by blood test because of the "peaks and troughs". The question arises of how long before the blood test should one stop medicating.....foggy73 was possibly in a "peak" moment at the time of her test?

Possibly the correct way is to go by how one feels. i.e. Lower dose if pulse raises too much, too hot, blood pressure change etc. Remains to be seen what the doctor will say!

I agree with you when you say that there cannot be any benefit to splitting the T4 dose because of its long half life. Apparently you can even take your prescribed daily dose, total it up, and take it once a week!


If it was me, I think I'd stop bothering with the levo dose altogether and raise the lio a tiny bit. It's doubtful it can be having much of an impact, being such a small dose.

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Thank you all for your replies. My consultant is amazing asks seems to know what he is doing with the combination. However he is retiring this month! ! I did have heart racing at night when I went to bed after 4 weeks of taking the T3 so he reduced the T4 to the alternate days twice a day which has solved the problem. My pulse was 80 when he checked it so I am happy with my current dosages. I did take my meds about 3 hours before my bloods were taken


And that's why the T3 is showing over range!



Ahhhh .. yes, that puts a different spin on things.

Experienced members will dose according to temps and symptoms …. I have done this myself during the winter months but Foggy has only just introduced T3.

I would say she needs to become familiar with T3 and how her body reacts to it before dismissing blood testing because of peaks and troughs.

T3 blood tests taken under identical conditions (ie same test timing, etc) will give like for like results and it is important to avoid overmedication and particularly over- range T3 blood test results which can be dangerous.



It is wise not to take thyroid meds in the hours before blood testing as a "peak" in hormone could be interrupted as over medicating and your meds reduced as a result.

I am pleased you are feeling well as T3 obviously suits you. Your endo sounds nice.

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I was on NDT & Cytomel for the last year but stopped the NDT this Sept as from the very 1st time I took the NDT, I had trouble with my breathing, couldn't seem to get my breath, couldn't stand for longer than 5 minutes and it drastically increased my fatigue to severe so that I couldn't even go for much of a walk anymore so I finally stopped it in Sept so have been on Cytomel only and am feeling wonderful. Well yesterday my doc tells me that based on my recent blood tests, I have no T4 in my body whatsoever and that I'm hyper now...but I don't feel nor act (and my husband agrees) hyper at all and in fact, I'm feeling THE best I've felt in over 20 years and this morning I was actually able to stand at the sink and wash all the pots and pans from last night in one go instead of having to sit down for 1/2 an hour after washing just one pot! She wants to put me on some T4 likely Synthroid but twice before I've tried Synthroid and each time it made my fibromyalgia flare up HUGE and hurt me like crazy. What do I do? I've already had an endo dump me when I was upped my Cytomel on my own and felt really good but he said he couldn't continue to prescribe it for me as he said it was too dangerous and he could lose his license. But Cytomel seems to be the only thing that's helped me so what do I do if this doc too wants to dump me 'cause my body doesn't fall in line with what the medical assoc. says it should?


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