Low TSH and decreasing T4

[Lita22]

Good morning. I've been having frequent blood tests as my TSH has been below range for quite some time. I had an appointment with the GP this morning and my TSH is even lower at 0.06 (sorry didn't get ref range). He advised that this indicates that I am over medicated, but said that he wouldn't decrease my dose of levothyroxine as my free T4 is currently in range.

He showed me my results on the computer and that as well as my TSH decreasing my T4 has also been decreasing over the past 5 tests from 16 to now 12 (ref range 9 -22). My GP said he'll retest again in 6 months.

This result seems a bit strange to me as I wouldn't expect both to be decreasing, so I was wondering if anyone could please offer some advice on why this would be?

The test was fasted at 8.30 on a Monday morning and I hadn't taken my levothyroxine for over 24 hours.

I currently take 100mcg 4x week and 75mcg 3 x a week . This I based on my current weight. I generally feel quite well at the moment but I do get episodes of fatigue and frequently feel cold

I did request a ft3 test as well, but told this wouldn't be done.

[SlowDragon Administrator]

Suggest you get FULL thyroid and vitamin testing

Request GP test vitamin D, folate, ferritin

Presumably you are still on B12 injections

What were results of thyroid antibodies testing last year

healthunlocked.com/thyroidu...

[Lita22 in reply to SlowDragon]

Thanks for your response. Yes I've had full vitamin testing recently, my levels are all good as I take vitamin d, folate and had an iron infusion last year .I'm still on b12 injections every 4 days as occasionally still getting nerve pain and this keeps it at bay and was at the recommendation of a specialist.

My thyroid antibodies tests were negative.