100T4/10T3 or 112.5T4/5T3

[LynLyn]

SeasideSusie Dear Seaside Susie and forum members. You have given me such wonderful advice for some time and I’m back again. I’d appreciate your input. I’m not sure what to do next and I need to see the endocrinologist soon. I’m not sure my conversion is good enough to be T4 only.

Please advise on my latest test results:

112.5mcgT4 and T3 5mcg Feb 23 (been on dose for 6 months)

TSH 0.33 0.27-4.2

T4 16.92 12-22

T3 4.10 2.8-7.1

100mcgT4 and 10mcgT3 May 22

Same reference ranges as above

TSH 0.06

T4 15.16

T3 6.36

Many thanks for taking the time to read this post and comment.

[SeasideSusie Remembering]

LynLyn

Did you feel better on one of those dosing regimes than the other?

May 2022 - 100mcgT4 and 10mcgT3

FT4: 31.6% through range

FT3: 82.79% through range

February 2023 - 112.5mcgT4 and T3 5mcg

FT4: 49.2%

FT3: 30.23%

Do you know if you are OK with a low FT4 and higher in range FT3 or do you need them both balanced?

It really is a case of no-one can tell you what's right for you, we're all different so need to experiment to find the right balance for us, only you will know where you feel best.

If those were my results the February 2023 FT3 would be far too low for me and I'd need FT4 over half way through range and fairly well balanced with FT3.

With the May 2022 results the FT4 would be far too low for me and I wouldn't need FT3 that high.

For me, I would leave Levo at 112.5mcg and increase T3 initially to 7.5mcg and retest in 8-10 weeks, see where FT4 and FT3 lie and tweak again if necessary.

[LynLyn in reply to SeasideSusie]

Dear SeasideSusie Many thanks for your excellent advice.

I’m ok but not ‘quite right’. In some ways I felt better last summer but again wasn’t ‘quite right’. I’ll try and persuade the endocrinologist to let me try 7.5mcg of T3. He’s not keen when my TSH becomes suppressed although he does look at T4 and T3 and knows I’m not over medicated.

I’m so grateful for your help. Thank you so much.

[SeasideSusie Remembering in reply to LynLyn]

LynLyn

I’ll try and persuade the endocrinologist to let me try 7.5mcg of T3.

You could be a little crafty here. Ask for 10mcg and if he refuses then ask him to compromise on 7.5mcg. If you get the 10mcg just take 7.5mcg.

He’s not keen when my TSH becomes suppressed although he does look at T4 and T3 and knows I’m not over medicated.

But as he's prescribing T3 he really ought to know that taking T3 does lower TSH often to the point of suppression. Is he banging on about suppressed TSH will cause osteoporosis and atrial fibrilation? If so that's only relevant in hypERthyroidism where a suppressed TSH and over range FT3 can cause problems. Suppressed TSH in hypOthyroidism is not the same. See:

LEVO DOSE SHOULD NOT BE DETERMINED BY TSH

Diogenes/Toft paper:

bmcendocrdisord.biomedcentr...

healthunlocked.com/thyroidu...

The link between TSH, FT4 and FT3 in hyperthyroidism is very different from taking thyroid hormone (T4) in therapy. In hyperthyroidism, FT4 and FT3 are usually well above range and TSH is very low or undetectable. In therapy, FT4 can be high-normal or just above normal, TSH can be suppressed but FT3 (the important hormone that controls your health) will usually be in the normal range. FT4 and TSH are of little use in controlling therapy and FT3 is the defining measure. A recent paper has shown this graphically:

Heterogenous Biochemical Expression of Hormone Activity in Subclinical/Overt Hyperthyroidism and Exogenous Thyrotoxicosis

February 2020 Journal of Clinical and Translational Endocrinology 19:100219

DOI: 10.1016/j.jcte.2020.100219

LicenseCC BY-NC-ND 4.0

Rudolf Hoermann, John Edward M Midgley, Rolf Larisch, Johannes W. Dietrich

LlINK TO PAPER:

ncbi.nlm.nih.gov/pubmed/320...

sciencedirect.com/science/a...

[LynLyn in reply to SeasideSusie]

SeasideSusie That’s amazing! Just what I need. I can’t begin to thank you enough. I’m going to print those out!

[SeasideSusie Remembering in reply to LynLyn]

Good luck, let us know how you get on.

[LynLyn in reply to SeasideSusie]

SeasideSusie Thank you, I will! 🤞

[LynLyn in reply to SeasideSusie]

Dear SeasideSusie I’ve been to see the endocrinologist and he agreed to 7.5mcg of T3! I have to go back in June for blood tests. Thank you SO much for all your guidance and support - I’m forever grateful.

[SeasideSusie Remembering in reply to LynLyn]

Excellent! I hope it works out well for you.

[LynLyn in reply to SeasideSusie]

Thank you so much 😊