Im confused regarding my latest thyroid results I seem to be over on my FT3. I was taking 175mcg of T4 and 40 T3 but recently upped T4 to 200mcg. Any increases I have had in the last year and a half has only slightly raised my T4 and kept T3 the same....sometimes it lowered. I had loading doses of B12 early dec....will this have aided conversion to T3?? And the absorption of T4? After the b12 loading doses my headaches were down to virtually zero but now 6 weeks later they are back. I am 99.9% sure I need more B12 but am now worried it could be T3? Although I have had headaches way before even touching T3. Any thoughts as back at gp tomorrow 😕

Back in Nov results were

FT4 12.5 FT3 5.4

I am now at FT4 22.3 and FT3 7.7 sure the upper ranges are 24 and 6.5ish?

10 Replies

  • Kirsty1946,

    Did you take T3 before your blood draw?

  • Head is a bit all over the place but 99.9% sure I skipped the night before and morning of test?! X

  • Kirsty1946,

    In that case you are mildly over medicated and may want to consider reducing either Levothyroxine or T3 dose slightly.

  • I had felt better on the increase until the headaches returned but I honestly think that is a B12 issue. My FT3 usually sits around 6 - 6.6 but dropped along with T4 after I stupidly took a flu jag so perhaps over is where I need to be. FT4 has never been above 15 I dont think...until now. Unless of course the B12 is helping the thyroid meds? So more B12 less T4 and T3? Oh to find a balance?! 😔

  • Kirsty1946,

    You increased T4 to 200mcg so that will have increased FT4 and FT3 levels.

    I don't know whether B12 will be helping thyroid meds or not.

    Contact for advice about B12 deficiency.

  • Thats one reason I am confused as I have increased gradually over probably more than a year and a half from 100 to 200mcg of T4 but my FT3 has always stayed the same....until the last increase x

  • Kirsty1946,

    Well the last dose increase seems to have raised FT3.

  • That was why i was thinking b12 helped conversion as I havent converted much before. If only I understood how it all worked! X

  • Kirsty1946,

    I don't know whether B12 will have helped conversion or not. It doesn't really matter, FT3 is over range so T4 or T3 dose should be slightly reduced so FT3 can drop back within range.

  • Thank you. Will speak with gp tomorrow. Endo was always happy with my slightly over range but perhaps I need to drop back to the 6.6 mark.

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