My daughter is taking T3 only, she has recently reduced her dose so is going to order a private test.
Last time she just ordered the FT3 test as I thought as she takes T3 only her TSH would be suppressed and T4 low anyway, am I right in thinking this ? or would it be best to have TSH T4 tested along with the T3.
Also how long after a dose reduction is best to wait before testing to get a true T3 level and do you leave 24 hours from your last dose before doing the test and is it best to fast for 12 hours.
Many thanks browny
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lucylocks
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Browny, if your daughter is taking more than 40mcg T3 her TSH and FT4 are likely to be suppressed and only her FT3 needs checking. 12 hours after last T3 dose is long enough but others will say 24 hours. Fasting is recommended when TSH is measured as it is lower before food and drink, other than water. If your daughter is self medicating she doesn't need to fast.
She reduced her dose a week ago so will it be O.K. to test in the next few days or should she wait longer. I know T3 gets out of the system pretty quickly but not sure how long to wait after a dose reduction to get a clear picture.
There is some confusion about the half-life of T3. In my case, I found it to be approx 12 hours (as the result of testing while I was on T3-only), but there are refs on the web that say the half-life is up to 2.5 days. The rule of thumb is that you wait 5 half-lives after a dose change, before testing.
It would be best to test TSH also, just to make sure it isn't too low. The AACE range of 0.3-3.0 is better than the common 0.5-5.0 range used by most labs, although I've seen some functional medicine practitioners recommend that it's OK to let TSH drift down to as low as 0.1. Don't let her get lower than this; if there's one thing that is worse than hypothyroidism, it's hyperthyroidism.
Do you happen to have any links to the references on the web, I have been searching and I cannot find anything.
I have just ordered my daughter a test for TST T4 T3 and she reduced her dose about 10 days ago so by the time it comes she should be O.K. to do it by your estimation.
You would think that en.wikipedia.org/wiki/Lioth... ought to be reasonably authoritative, but that site claims the biological half-life of liothyronine is 2.5 days. Which does not match my experience, or what I've been told by my doc.
You could try googling "liothyronine half-life". Many of the refs state a half-life of 2.5 days. The question is, does your daughter want to wait as long as 5*2.5=13 days for retesting? If she's willing to wait that long, then you can be sure that you've reached a steady state after dose change.
Whilst some of Wiki is amazingly good, it does have lots of things that are questionable.
Half-life of a substance in a complex biological system is very different to radio-active half-lives. In a hypothyroid person, the effective half-life of T3 is much shorter. And in a hyperthyroid person, it can be much longer. Further, whereas radio-active half-lives can be shown to be phenomenally stable with a literal halving in every half-life period, with T3, it also depends on how much is in the system.
well she is actually feeling worse but instead of raising her dose we thought would get her tested to have insight of what's going on.
In June she was on quite a high dose of 100mcg, and her T3 was over range. I do not have the figures with me as she does not live with me but I think top of range was 6.8 and her level was maybe 7.6 so she reduced to 50mcg.
She did not have any over dose symptoms.
She recently reduced to 25mcg. as she was getting episodes of loose stools and sweating but she is now back to sleeping all day so the reduction has made her feel worse.
Maybe the tests will hopefully tell us what is going on.
I would contact Shaws on this forum, about Dr. John Lowe and his use of t3 and links to information. He found Wilson's totally useless, as some, like me and your daughter, have low temps, that stay low and have been low for many years, before the thyroid symptoms showed up. Thyroid meds don't raise my temps. But since getting Hashimoto's, my temps are not stable, sometimes i feel feverish, but am normal.
Many people have thyroid hormone resistance and need a dose that causes the ft3 level to be shockingly high, in order to relieve symptoms, yet they have no hyperthyroid symptoms at all and feel better/well.
T3 is dosed by improvement of symptoms, not labs or the dose would always be kept too low. As you see, she felt well and is now ill, upon a dose reduction that is based soley on labs. Most on here, on t3 only, have to buy their own meds online, because doctors will not let them dose to the point of doing well. This doctor will keep her ill.
Hi browny it's good your daughter has you in her corner... I've read this discussion and agree with all the threads .i just wanted to add that when reducing or increasing T3 do it gradually and in small increments ..harder I know with some tablets to get a half or quarter tablet ,some are marked but I've have found a razor blade helpful for cutting... To big a rise or fall in T3 dosage causes. Shock to the system .... Slowly does it ... Also it won't wirk correctly if all your daughters other body building blocks are low ... Vit D Iron B12 magnesium +++ all need to be at optimum levels for the T3 to work correctly ...( you mentioned sweating) ... Hope she gets sorted soon .
my daughter takes all the recommended supplements and more besides.
Her iron was very low at one time but she continually supplements with it otherwise if she stops it her level drops again. She also uses progesterone cream for her PMT which she has had some success with.
Were you suggesting something may be amiss which is causing her sweating ?
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