FT3 levels dropping over time - what to do?

[Bearo]

When I started on Levo about four years ago I seemed to be a good converter. I’ve had some fluctuations in dosage and every time I’ve rechecked FT3 it’s gone down. It never goes up. I now seem to be a poor converter.

2021 on 100mcg Levo - weight loss on this dose and frequent number twos

TSH 0.01

FT4 24.9 = 129%

FT3. 6.5 = 91.89%

2022 on 85mcg (my reduction)

TSH. 0.02

FT4. 18.2 = 62%

FT3. 5.1 = 54%

2023 on 75mcg (GP reduction) increased depression and painful slipping jaw, shoulder pain

TSH. 0.02

FT4. 18 = 60%

FT3. Not measured

2024 on 89mcg (my increase)

TSH. 0.01

FT4. 24.4 = 124%

FT3. 4.8 = 46%

2024 - on 85mcg (my decrease)

TSH. 0.01

FT4. 20.4 = 84%

FT3 4.8 = 46%

2024 - Oct - on 85mcg

TSH 0.02

FT4 19 = 72%

FT3 not tested

2024 - Nov - on 75mcg (GP decrease)slight increase in lethargy/depression, plus tendon type issues

TSH 0.04

FT4 18.2 = 62%

FT3 4.1 = 27%

The ranges were FT4 12-22 or one is 11-22. FT3 range is 3.1-6.8.

So anything above 89mcg is too much for me and 75mcg is not enough. I’m back on 85mcg

My vit d is around 100, B12 is a little under the 500 mark,so could be higher, folate and ferritin are ok, iron bumps along the bottom of the Full bloods cut off point. I’m 71 and have never been on HRT.

My HbA1c is 43 putting me in prediabetes range. I’ve been trying to improve diet but only recently trying to avoid too many carbs…..not enough to affect conversion, I wouldn’t have thought.

is it time to try to source some Lio or are there things I should do to improve conversion?

Or, as no obvious symptoms when I’m on 85mcg Levo do I just plod on?