Does T3 level change on thyroxine?: Can you... - Thyroid UK

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Does T3 level change on thyroxine?

richard123 profile image
5 Replies

Can you please advise if normal for t3 to remain at exactly same level despite T4 Level changing? I'm in 75mcg but t3 is 4.1 and has stayed at exactly that on and off treatment??

Thank you

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richard123
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5 Replies
greygoose profile image
greygoose

No, it's not 'normal', but perhaps you have a conversion problem.

But, then again, you're not on a very high dose of levo.

Can you give us all your results, with the ranges, please. That will give us a better idea of what's going on.

How long have you been on 75 mcg levo? Does your doctor keep changing it up and down?

richard123 profile image
richard123 in reply to greygoose

Thank you I don't have ranges but at diagnosis TSH was 28 t4 13.3 on 75mcg TSH is 8.3 and T4 is 17.2 but t3 was 4.1

Through out. I'm off to Addenbrooks tomorrow and would be helpful to know if I ask for T3 would it help as if I go over 75mcg after a week I'm anxious, fast jumpy heart races and I feel awful. I've been on 75 for around 10 mths

Thank you

greygoose profile image
greygoose in reply to richard123

I'm afraid it is impossible to tell how well you are converting without the ranges. Ranges vary from lab to lab so we need the ranges used by your lab to make sense of the results.

If going above 75 on T4 makes you anxious, T3 could make you more anxious, because it is the active hormone. T4 is the storage hormone. But, with a TSH of over 8 you are seriously under-medicated. It should come down to 1 or under. I think it's best to be correctly treated on levo before thinking about T3.

When you have a blood test, always ask for a print-out of your results. That way, you will get the ranges included. :)

shaws profile image
shawsAdministrator in reply to richard123

Do you get the very earliest of blood tests? Fasting? You can drink water - and allow a gap of 24 hours between your last dose of thyroid hormones and the test and take afterwards? If not you wont have optimum results which could show you need an increase.

The aimis a TSH of 1 or lower with FT4 and FT3 in the upper part of the ranges. An increase of 25mcg levo every six weeks is in order to attempt to get the above results.

Also ask for B12, Vit D, iron, ferritin and folate as deficiences in these also cause symptoms.

SlowDragon profile image
SlowDragonAdministrator

75mcg is a very low dose

You have probably been left of too small a dose for far too long. It can be difficult to increase dose. Some people have to increase dose very slowly

Low vitamins can badly affect Thyroid hormones

Hope your Addenbrooks endo tested vitamin D, folate, ferritin and B12

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