T4/T3 levels dropped

[nat10]

Have another phone call tomorrow with GP, so have a quick question.

On 100 thyroxine sept to nov

blood test nov 21 TSH0.01 T4 19.3 T3 5.4

100/75 thyroxine dec to feb, back to 100 thyroxine from March

May 22. TSH0.01. T4 18.2 T3. 4.9

Ranges the same, T4 12-22 T3 3.1-6.8

Is it normal for T4/T3 levels to drop as your body adjusts to taking thyroxine? Or is it because my dose keeps changing?

Thanks for any advice.

[tattybogle]

in real terms these is not much difference between those T4 and T3 levels , it's no more than the sort of variation you would see over a normal day. eg . it's possible that if you'd tested the next day instead (or an hour earlier /later than when you did ) you could have got T4 19.6 and T3 5.5 and be thinking your levels had gone up a bit, not down .

[nat10 in reply to tattybogle]

Thank you for your reply and explanation.

[SlowDragon Administrator]

Do you always get same brand levothyroxine at each prescription

Always test thyroid levels early morning, before 9am and last dose levothyroxine 24 hours before test

Important to test vitamin D, folate, ferritin and B12 at least once a year

What vitamin supplements are you currently taking

Reducing dose levothyroxine often lowers vitamin levels

Do you have autoimmune thyroid disease, also called Hashimoto’s diagnosed by high thyroid antibodies

[nat10]

Thanks for your reply.

Did have a short change of brand (4days) mercury, started to feel like I was getting a cold /tired so went back on to North Star but still feel the same , bloods were done 2weeks after going back on North Star.

Ferritin was checked in feb 85.1 (15-150)

Vit d was rejected but was 175 in June 20

Folate tested August 21 5.7(3.3-19.3)

B12. 615 (197-771)

Now taking a b complex tablet

Also take low iron supplement, flaxseed, gut health,magnesium, vit k, vit d in winter.

Diagnosed with hashimotos and test was done 24hrs after thyroxine and before 9.