my FT3 levels have never increased on levothyroxine, in fact before starting Levothyroxine properly I had the highest FT3 result of 5.6 (67%), since starting levels have fell to around 5.1/ 4.8 (48-54%), even down to 4.2 once. it seems the higher the ft4 the lower the ft3. I feel very bad when my ft4 levels get over the range so am worried that FT3 might cause this response, however I also havnt felt amazing when hypo, wondering if I have a conversion problem and a lower dose of FT4 + a bit of FT3 could be good?
Please also note I am seemingly having an issue where TSH is not indicating high FT4 and hyper symptoms.
here are some example results:
July 2023
TSH 7.3
FT4 21.9 (12-22)
FT3 5.1 (3.1-6.8)
May 2023 (feeling hyper)
TSH 2
FT4 22.9 (12-22)
FT3 4.2 (3.1-6.8)
May 2023
TSH 3
FT4 26 (12-22)
FT3 4.8 (3.1-6.8)
August 2022
TSHS 4.05
Free T4 19.8 (12-22)
Free T3 5.3 (3.1-6.8)
August 2021 (obviously very hypo)
TSH 15
FT4 16 (12-22)
FT3 5.6 (3.1-6.8)
Sam
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samking5
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Oh dear, sorry, we absolutely need the ranges for those results. Ranges vary from lab to lab so we need the ranges that came with your results. Without them, the results are meaningless.
That said, it's very likely that you are a poor converter, looking at those results. And, a TSH - a TSH is always a TSH - of over 7 is much, much to high for someone on thyroid hormone replacement.
Rather doubtful you were 'hyper' with a TSH of 2, but your FT4 does look high in May. Be wary of symptoms because so many of them can cross over from hypo to hyper, and what we think are hyper symptoms can actually be indicating hypo.
Well I know technically below 0.27 is suppressed however I have definitely had hyper episodes where my tsh wasn’t suppressed but ft4 was high. I’ve heard of other people crossing into hyper when tsh is not supressed. I am thinking one reason could be that levo only therapy does not mimic bodies natural production and so pushes up ft4 too high without such large changes in tsh ( and in my case no change in ft3)
You can't 'cross over' into hyper if you're hypo. It doesn't work like that. You can be over-medicated - or, if you're a poor converter, your FT4 can be too high and cause symptoms. But that is not the same as being 'hyper'. And, in that case, the TSH would not be suppresse - which is more like 0.03 than 0.27 - because the FT3 is still too low.
And, you are a poor converter. So, the question remains: is it the high FT4 causing the symptoms or the low FT3? It's usually T3 that causes symptoms when it's too high or too low, because T3 is the active hormone. T4 is basically a storage hormone that doesn't do much until it is converted into T3. But, some people do react badly to having their FT4 too high.
But, in answer to your original question: yes, adding some T3 to a reduced dose of levo would probably help you no end.
Notice how your fT3 goes up and down with your TSH.
When TSH is high it drives the thyroid to make a greater proportion of T3 to T4 than it usually does , and it also increases the rate of conversion from T4 to T3 within the thyroid.
It's a kind of emergency 'boost' to T3 (to try to keep the body's levels of T3 up even when thyroid is failing)
This is why before you took any levo , your fT3 was highest .. when you take levo and the TSH lowers a bit , this emergency 'boost' function is then turned down a bit ..... so you get lower fT3 levels again .
I ask this question because my unintentional undereating and low carb caused higher TSH and lower FT3 despite top of and over range FT4 levels. The higher I raise my Levo the less hungry I feel. May not be the reason for your increased TSH but from personal experience it was the first thing that came to mind.
I'm having the same issue!! My integrative doctor is now using a compounding pharmacy because I told her I NEED some T3 added. My TSH was very high, my T4 was over range, my reverse T3 was high in range, barely in range, very high but my T3 was tanked. In range but at bottom. The only thing I'm doing different is I started Intermittent fasting and I've lost weight, inflammation, and I feel like I'm healing in many ways. They've lowered my dose from 112 to now 65 mg levothyroxine with 5mg of T3 added. I felt great on each lowered dose for about 2 weeks then feel hyper again. The heart palpitations are the worse. I'm not converting well or my body is turning T4 into Reverse T3 for some reason. It's very expensive to keep changing my dose and the doctors don't know what to do with me. My theory is when fasting your body isn't using a lot of energy so you don't need as much thyroid medication. So we keep lowering I guess until I find a dose that I can just stay on. So far that hasn't happened and it's been 2 years and my palpitations are not going away and now I'm going to see a cardiologist to rule out heart issues. Ugh
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Levels worse after starting levo
Increasing TSH with normal T3 levels. 
What next: should I reduce Levo and increase T3?
