A brief recap from two weeks ago - I'm 63 yrs on stage 4 cancer treatment but keeping well and active (6 mile walks). I've been on levothyroxine since age of 4 yrs (congenital hypothyroidism - Pendreds). The thyroxine dose was as high as 300 mcg throughout my 20's and 30's and was reduced to 200mcg after my two pregnancies at 35/39 yrs. My free T4 has stayed stubbornly high over past few years and TSH very low even when reducing gradually to 125 mg from 200mcg. My GP practice would like me to continue to reduce my levothyroxine to 100mcg daily but I feel cold, sluggish, my nails keep breaking, and despite the cancer meds that initially gave me a 4x daily habit, I'm now down to once daily and slightly constipated. I also have gilberts syndrome which can affect T4/T3 conversion. I drink 2litres water daily, take 100-125 mcg levothyroxine one hour before breakfast and 2-4 hours before other meds and take my calcium supplements in the evening. The levo generic brand keeps changing. My blood results as follows:
GP march 2022 125mcg Free T4 28.5pmol/L (range 9-24) TSH 0.11 mU/L (range 0.2-5)
GP Dec 2021 150 mcg Free T4 24.3 pmol/L TSH 0.11 mU/L
GP Dec 2015 200mcg Free T3 4.1 pmol/L (no range given)
Blue Horizon march 2022 Free t4 21.4 pmol/L (range 12-22)
Free t3 4.4 pmol/L (range 3.1-6.8)
TSH 0.19 mU/L (0.27-4.2)
Cortisol random 508 nmol/L (166-507)
Thriva April 2022 Active B12 80 pmol/L (37.5-150)
Ferritin 106ug/L (44-150)
Folate 11.8 nmol/L (8.83-30)
I can up my folate though believed my diet was quite varied/optimal. My question is whether I should keep reducing the thyroxine and feel hypothyroid or hold out to stay on this 125mcg dose and see whether introducing tri-iodothyronine might help in reducing T4? As the oncologist said, I'm a bit complex!
Thank you in anticipation, Bikebabe.