Time for TSH suppression to stop?

[patchworkcat]

How long would it take for TSH to rise after suppression with T3. As you may see from previous post I stopped T3 for 3 days prior to a blood test ( incorrectly it would appear) and while my T3 level had dropped my TSH was still suppressed. Prior to 2 years on T3 I was on Levothyroxine for 4 years and my TSH rarely was below 2. Thanks for advice.

[greygoose]

Why do you want your TSH to rise?

[Angel_of_the_North]

Impossible to say. With primary hypo, if you take no meds at all your TSH will probably rise in a week or two, may be a month, but you'll be very ill. With central hypo or if you have previously had Graves or been on meds for a very long time, it might not rise in years. It's not worth jeopardising your health to placate a TSH-obsessed doctor

[diogenes Remembering]

TSH responds (or doesn't) to changes in treatment by a process called hysteresis. This means there is a big lag in response after any change up or down. It can be weeks and months and if you've taken T3 for a long time maybe never.

[patchworkcat]

If you read my previous post you will see what has been said and a response that said in 3 days my TSH should have been on the rise. I wanted to know what others thought. Thank you, I have been referred to an endocrinologist and lots more blood tests with query pituitary cause, but you have informed me that the fact my TSH hadn't risen in 3 days is not unusual, thanks.

[SlowDragon Administrator]

On any T3 dose TSH is invariably suppressed. Most important results are FT3 and FT4

Also essential to test vitamin D, folate, ferritin and B12 too

If your TSH was over 2 then you probably weren't on high enough dose of Levothyroxine

Recommended on here that all thyroid blood tests should ideally be done as early as possible in morning and fasting. Do not take Levothyroxine dose in the 24 hours prior to test, delay and take immediately after blood draw. This gives highest TSH, lowest FT4 and most consistent results. (Patient to patient tip, best not mentioned to GP or phlebotomist)

If/when also on T3, make sure to take last dose 8-12 hours prior to test

Is this how you do your tests?

Private tests are available. Thousands on here forced to do this as NHS often refuses to test FT3 or antibodies or vitamins

thyroiduk.org.uk/tuk/testin...

Medichecks Thyroid plus ultra vitamin or Blue Horizon Thyroid plus eleven are the most popular choice. DIY finger prick test or option to pay extra for private blood draw. Both companies often have special offers, Medichecks usually have offers on Thursdays, Blue Horizon its more random

[radd]

patchworkcat,

My TSH level has never risen no matter how much/little thyroid hormone replacement I have medicated, since I started testing after starting thyroid hormone replacement 8 years ago.

And a suppressed TSH level does not always accurately gauge whether exogenous thyroid hormone is adequate, sufficient or excessive anyway.

TSH is made by the pituitary (in the brain) and there can be issues within the pituitary gland itself but also the hypothalamus, adrenals, immune system, or nutritional/iron deficiencies that are influencing the body’s assessment of how much thyroid hormone is needed (ie a down regulation of the hypothalamic/pituitary axis or blunting, or for any reason the feedback loop is not functioning correctly).

TSH levels also won’t tell you if you are converting T4 - T3 well, converting too much RT3, have elevated thyroid antibodies attacking your thyroid gland or have iron/nutrients deficiencies. Also infection, aging, depression, even excess caffeine all influence TSH levels.

Why would you wish to even consider TSH results ? ? ..

[diogenes Remembering]

If you are interested more in what hysteresis in TSH response really means, this paper describes it:

REVIEW ARTICLE

Front. Endocrinol., 14 June 2016 | doi.org/10.3389/fendo.2016....

A Review of the Phenomenon of Hysteresis in the Hypothalamus–Pituitary–Thyroid Axis

Melvin Khee-Shing Leow

Freedownloadable