Maybe you can offset it with a bit of lithium? It should have the opposite effect to inositol. It's like in "Alice in Wonderland", when you take a bite from different side of the mushroom to find the right balance.
Huh... Do you take orotate or another form? I took 30 mg of LO per day at one point and my lithium level was still undetectable.
Another reason could be that maybe this peripheral conversion is linked to hypothalamic settings only works with a certain type of neurochemistry but not with others. Do you think you might be more on the bipolar spectrum like me and @BadBadBear, i.e. have you ever precipitated hypomanic episodes with drugs/supplements/hormones, do your symptoms fluctuate and change frequently, or are you very stable/unipolar by nature? I'm definitely more toward bipolar side and I noticed that my T3 is prone to wild fluctuations both from a number of factors.
My symptoms do fluctuate and change, though very little from supplements and mentally I'm very stable.
Took some lithium orotate (with 5mg elemental lithium), but since a couple of years take a high Mg Mineral water (contains 1 g per lliter; Rogaska Donat Mg), which also contains 3mg of elemental lithium. Got about a liter per day.
My last lithium whole blood test 3 years ago came still back at 0.06, and 6 years ago at 0.05. But at that time I already started with the mineral water.