Is there a test for reverse t3?
I may be reading too much into things but I'm a bit worried this could be happening to me
My iron and ferritin levels are on the floor!!!
I've never been so stressed in my life, my daily routine makes me shake where I'm so stressed, my poor kids get shouted at a lot 😢
Natj, Genova and Blue Horizon do reverse T3 and FT3:rT3 ratio tests. Generally it is unconverted T4 which creates high rT3. You are taking so little T4 I think it is very unlikely you will have an rT3 problem.
But I'm taking a lot of t3, or does that not turn into reverse t3?
No, it doesn't. rT3 is formed when the wrong atom of iodine is removed from a molecule of T3, so that it doesn't fit properly into the receptor. And the problem then is that the receptor is blocked, so the good T3 can't get in. But once the rT3/T3 is formed, the only thing it converts to is T2. 
Or T1, I believe.
So going from that then possibly my t3 is just not working? I'm very anemic and I think that has a lot to do with it, I have gp Monday and I think until I get my ferritin/iron raised its pointless me taking the T3!
I'm more tired now than I've ever been, I ache like I've got flu!
I actually thought I was on to something!!! Ha ha
Thanks grey goose
Perhaps you're just not on enough T3. I very much doubt that the T3 isn't working. Why wouldn't it work? Yes, you need to optimise your ferritin, but Don't stop taking the T3 because of that. It may not be making you feel well, but it's keeping you alive!
Natj, no, it's only T4 which converts to rT3. It's natural for the largest proportion of T4 to convert to T3 and a smaller proportion to convert to rT3 as a brake on over conversion causing hyperthyroidism. There may be problems with large amounts of unconverted T4 turning to rT3 which may prevent T3 entering cells but this is unusual in people taking low doses of Levothyroxine.
I thought I may have been on to something then, well my gp seemed to think that my minute dose of levo would push my ft4 level into 'normal'!!
But they only test the tsh now!!! Doesnt make sense?
If you're taking T3, your T4 is bound to be low, and it's not really a problem. Dépends on how much T3 you're taking. Doctors just Don't really know what 'normal' is. 
My t4 was only 0.5 below the range, so only slightly low but I was symptomatic so they treated!!!
But I wasn't taking T3 then , just prescribed 25 mg levo x
Ah, ok, I see. Well, there does seem to be an absorption problem, then, doesn't there. Not just a conversion problem. Have you had your gut investigated? For Ceoliac and stuff?
Previous bloods for coeliac were negative but of course they just label anything they don't know as 'ibs' x
Yup. They have a list of categories they shove things into : depression, anxiety, menopause! - your age, at any rate, high stomach acid, ibs, asthma is another one... the list goes on - anything they can just throw a pill at rather than look for the cause.
You often get false négatives with blood tests for Coeliac. There are better tests, but...
Yes I agree
I'm having a barium meal X Ray snd possibly another endoscopy which they will then take a biopsy of ulcer which will also check coeliac too!! But would like to avoid endoscopy if possible
Were you eating plenty of gluten containing foods before being tested ,eg gluten at 2 meals a day for 6 weeks ? If not then a negative result could be false ! X
Natj, 25mcg might just have pushed FT4 into the bottom of range but unless dose was increased until FT4 was in upper range you wouldn't have felt any better. I think it's scandalous that doctors think TSH only testing is sufficient.
Apparently the lab will only test the tsh if your already taking thyroxine!! Not the gp fault as they told me on the phone!!! Oops!!
I am afraid I consider it the responsibility of the entire medical profession - including your, my and everyone else's GPs.
They exercise their collective power so very successfully in some areas but have allowed their valid test requests to be denied. Of course labs might need to refer back to doctors - sometimes even to tell them they don't know what they are doing - but the doctor should have primacy.
rT3 can be assayed but it is expensive. I have never bothered. The question is what does the result mean? Nobody really knows how to interpret the results. There are some obscure conditions where the rT3 is elevated but these are usally associated with quite dramatic changes in thyroid hormone levels.
rT3 measures the total rT3 not the free rT3. I don't know to what extent rT3 binds to serum transport proteins such as TGB and transthyretin. rT3 can bind to thyroid hormone receptors and because it is inactive it will block the receptors. However, I haven't seen any research that determines the relative affinity for the receptors. Which is 'stronger' the fT3 or rT3? Nor have I seen any research into how rT3 is transported into the cells (as T3 is). In plain English, nobody seems to be able to quantify the effect of rT3. i.e. how much rT3 is harmful.
So if you get your rT3 measured it will be almost impossible to interpret the result. rT3 increases when thyroid hormone levels are high, especially if fT4 is high.
Thank you for that
I had to read it a few times to sort of understand it, but I think I get the gist of what your saying
My worry is that I'm taking 25 mcg levo, just over 30 mcg t3
But I've gained half a stone in 3/4 weeks
My belly is huge and I feel Rediculously uncomfortable!!
I don't handle situations well I get extremely stressed out, cry 5/6 times a day and it all pointed to rt3!!!
There seems to be little understood/known for sure about the transporting of rT3 across cell membranes and the blood-brain barrier. It has to get into cells before it could possibly block a T3 receptor.
And fully agree about it being the Total rT3 that is measured - an oft-missed point.
Interesting info..
I don't know who this Dr Fairchild is ! ! . / .. but he claims ......
.. ..[.... ... In some cases, the ability to slow down metabolism by producing reverse T3 can be a survival advantage. People of Irish descent, for example, or anyone from a culture that has historically had to survive famine, had a survival advantage from being to produce more reverse T3. Those who could slow down their metabolisms could survive better in times of famine than those who had active metabolisms and could not slow them down.. ..]... ...
A bit like a little hedgehog hibernating ..! ! ..
F
sufairchild.com/ENDO/thyroi...
Something vaguely familiar about the slowing down (but not the doctor - never seen him before). And I have a strongly Irish genetic background! (But no hedgehogs in the family that I know of.)
I feel that for all the snippets of information about rT3 that are mentioned, sometimes frequently, there are other aspects which are ignored. For example, rT3 can be deiodinated to T2. So, for all its own apparent lack of activity, rT3 could actually act as a transport mechanism for delivering T2 (and an atom of iodine)...
Re Irish ancestry .. I know.. that's why I sent it.!
Re link
Don't understand most of it except least sentence.....[...We conclude that rT3 is a most important precursor of T2' whereas T3 contributes only to a minor degree to the total T2' production under physiological conditions....]
ncbi.nlm.nih.gov/pubmed/716776
F
Ah but! That is T2' which is 3,3′-T2. Plain T2 is 3,5-T2. Also called 3,5-diiodo-l-thyronine.
These links explain more:
pubchem.ncbi.nlm.nih.gov/co...
pubchem.ncbi.nlm.nih.gov/co...
Look at where the iodine atoms are in the diagrams.
Still interesting. And leaves us asking what the effects of T2' are...
.. (. sigh .. )..... as in .... "way over my head..! ! ''
F
It's not!
The diagrams show the basic structure of thyroid hormone.
There are two hexagons. These are rings of carbon atoms. (Think of wheels on a bicycle, if you like.)
In one version, both iodine atoms are attached to the same ring. In the other one iodine atom is attached to each ring. That is, in the first case you have tied two bits of string to one wheel. In the other you have tied one bit of string to the front wheel, and the other bit to the rear wheel.
Snap!!! 😁😁😁
Hello Natj,
You are optimally dosed....
I would say unless you have someone to interpret your results and treat you accordingly ... it is not worth getting RT3 tested as generally endos consider it an inactive metabolite without any effects so wouldn't consider it. .. and probably couldn't read test results correctly either..! ! / ..
Reverse T3 is converted from T4 and is the bodies emergency brake. Too much is caused by any of the reasons that give us thyroid imbalances in the first place....
Treatment includes T3 which endos aren't keen to prescribe .. and will surpress a TSH levels ... and endos aren't keen on that either..! ! //.
To the uninitiated doctor you would be viewed as HYPERTHYROID even though you probably would be feeling great..! ! ..// .. .
To treat using RT3 results means also considering sex hormones in combination with symptoms and doctors don't usually consider those..! ! ! ... either......
Natji, Clutters response to thread ..
" healthunlocked.com/thyroidu... "
....... is the clue.. {. .. symptoms can lag by up to 2 months after biochemistry is good. ...} ....
Hope you feel better soon,
Flower
Thank you flower, I just can't believe how quick I'm gaining weight!
I'm seeing my gp Monday and want to get my vitamin s tested and ask how they are going to deal with my anemia because I'm getting nowhere fast on the gentle iron and cannot tolerate anything stronger
Also a friend of mine that started on t3 noticed a difference straight away!
So of course I expected too also x
Natji,
Hormones are so immensely complicated ... really no "one" answer fits all.
A lot of people do well when T3 is introduced including myself but you obviously have many other issues influencing the usage of your thyroid hormones.
I realise it must be difficult for you and recognise how desperate you are .. ( .. I have my own "desperate" issues too so can fully empathise .. ) but you need to be patient. Until you give the necessary time frames for hormones to settle .. it is pointless adding or subtracting anything. Your anaemia will be further complicating matters.
Stop grasping at straws and concentrate on looking after yourself, addressing deficiencies and getting thyroid hormones to work properly.
You have chosen to self medicate after ONLY a month on Levothyroxine.... Your poor body needs TIME to recover to the adjustments and acclimatise to the new MUCH NEEDED hormones ..... but unfortunately this can take time. ... ..
Post as much as you want to ..... you know you have LOTS of support here as many of us as experienced what you are going thru ....
Flower ((hugs))
Thank you flower, I feel I'm probably making a nuisance of myself, I regret now what I've done but so desperate to get a bit of life back hence me rushing into things, I'm a fool to myself, I'll try and sit it out a few more weeks now
I need to get my vitamin d and b12 bloods done right? Xx
Yes you definately do ! ! !... but WE are ALL impulsive sometimes as are so wanting to get BETTER..
You are NEVER a nuisance ... well .. no more than myself and rest of 'em..! ! !
F
I really do not know where I would be without you lot honestly thank you so much x
Thank you so much
That last paragraph is almost identical to the one I read which made me wonder about the possibility of rt3!!!
I will look into the iron, I'm also going to look st other links now
Many thanks
Natalie
HI Natj123, it is the T4 that turns into T3, but I am very low in both irons, and high cortisol, you sound as if you probs have high cortisol with stress as well. My doc is at loggerheads with the endos in Newcastle, I am not allowed to get the other tests done as well, doing only TSH T3 and T4 only gives part of the complete picture, they really are stupid, what else can we think, or is it the money!!!
Blue horizon are emailing me back with the prices of the bloods that I want done, 11 in total, if they're too expensive, will have to wait till I go back to Crete, very cheap and quick results there.
I am wanting DHEA, 24hr saliva cortisol, B6 and 12, selennium, zinc,chromium, RT3 and the 2 anti-body tests, iodine. Then I will be satisfied, first which hypo I have, more than likely Hashis, and also, do I have too much RT3, the ratio is meant to be 10:1, sites differ. I'll stick with that one though.
Good luck with the battle
I can't afford tests either it's sad!!! But I did buy myself some vit b12 and d3 to see if that will help a bit I can't believe I'm taking t3 and still gaining weight!! My iron is very low too!!! X
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