How much t4 does the body store?

Can the storage be exhausted? Or does the body immediately use the t4 to make t3? Just a sick guy at home trying to get all the answers lol... and a little bored

[Lalatoot]

The half life of t4 is around 7 days. That means what you take today will be half gone in 7 days. The storage could be exhausted if you stopped levo or were undiagnosed - this is called a myxedema coma and is life threatening.

Now the storage of ft3 is something else. That is your homework for tomorrow!

[Hidden in reply to Lalatoot]

Thanks 🙂. I worded that wrong ,I meant to say is there an amount the body can store before it says I have enough t4 and just throws away the extra you take in? Does it store the t3 that you take orally? Or does that immediately get used?

[Lalatoot in reply to Hidden]

Half life of t3 is about a day I think.

[Lalatoot in reply to Hidden]

You get to a point when the body has too much t4. This is called a thyroid storm and is really serious.

[Hidden in reply to Lalatoot]

I didnt know that. That's helpful. So hypothetically a person who is poor at converting t3 could be taking a high amount of t4 that creates an optimum level of t3 but the t4 is too much and can create hyperthyroid symptoms or even worse thyroid storm.

[Hidden in reply to Hidden]

It's not likely that a poor converter would end up with optimal FT3 levels even on high doses of T4 since conversion is impaired. That is how you know someone is a poor converter, BTW - high FT4 levels, low FT3 levels.

The body has a way of disposing of unwanted T4; by converting it to an inactive form of T3 called reverse T3 or rT3 for short.

[Lalatoot in reply to Hidden]

Don't think that is how it is. Why not google search thyroid storm and read up.

[greygoose in reply to Lalatoot]

I really don't think that's the definition of Thyroid Storm:

healthline.com/health/thyro...

As Hidden said, the excess T4 from exogenous sources would get converted to rT3 long before that happened.

[Lalatoot in reply to greygoose]

Yes I realised that when I went over it following the reply which is why I suggested they google it for themselves.

[helvella Administrator]

In a person without any thyroid disorder, a significant amount of thyroid hormone is stored within the thyroid itself.

In everyone, a significant amount of thyroid hormone is stored in the blood, bound to proteins (thyroid binding globulin, albumin and transthyretin).

If you look at the ratio of, for example, Total T3 to Free T3, there is typically around three hundred times as much bound to proteins as there is free. The binding mechanisms enable thyroid hormone to be carried safely in the bloodstream.

[Hurtlocker in reply to helvella]

Hi there...a penny has just dropped re.your post...all my bloods come back "normal" within range !!! But still feel dreadful most if the time. Results shows I am converting T4 to T 3. Could I just be a poor converter!!as I run out of all energy after 3/hours and have to lie down..can go on again before it all happens again.am trying to take meds at night so I feel better in day but not working..shattered again by 11am..what am I doing wrong .on 75mic Teva Levo..have tried other brands but same result!!Endo says he can only treat what he can see!!,i.e normal bloods and conversion to T3...help...