Reverse T3 Test

[lucylocks]

Hi

Can a Reverse T3 test be done whilst on T3 medication?

Thank you browny

[Emerald]

Sorry I can't help you but thanks for asking this question I await replies as I am on T3 and I don't understand the implication of rt3.

[lucylocks in reply to Emerald]

Hi

see reply and link from humanbean.

[jimh111]

The literal answer is that it can be done. However, I'm not sure if an rT3 test is of any use at any time and certainly of less use if you are on T3. If I understand it correctly the rT3 assay measures total reverse T3 and of course it's the free hormone levels that matter. I think the rT3 figure is only useful if it looks very high or very low. I've never seen any research that could give an indication of how rT3 'competes' with fT3. i.e. once you get the number what does it mean?

I'm speculating here but I don't know how you would make any use of the rT3 number once you have it. I don't think anyone has worked that out. Maybe one of TUK's advisors could give advice on whether the rT3 figure can be informative, other than if it is simply unusually high or low.

[lucylocks in reply to jimh111]

Humanbean has supplied a very good link re T3 and Reverse T3

[greygoose in reply to jimh111]

Jim, I think you're muddling rT3 with TT3. An rT3 test only measures rT3, not total rT3, because RT3 doesn't bind with proteins, just with receptors.

TotalT3, on the other hand, tests bound T3, rT3 and FT3, and is totally useless.

But if you have something that says otherwise, I would very much like to see it.

[jimh111 in reply to greygoose]

Apologies if I've got it wrong. I remember asking a lab if rT3 was a total or a free assay and they said total. I can't find the e-mail now. However if rT3 doesn't bind proteins then the total and free fractions are the same. I've always thought total T3 was unbound T3 plus bound T3. i.e. no rT3. But I've never checked this.

There is so little research on rT3. Which receptors it binds to and what its affinity is compared to fT3. What are the cellular transport mechanisms and how they compare with T3. Because of all these unknowns I've taken the view that you can't do much with an rT3 number and as it's an expensive assay it is better not to bother.

[greygoose in reply to jimh111]

If you look on a lot of American forums, they're always going on about rt3 testing - alright for them! lol But they never really explain what it's all about. I think it would just tell you that you aren't converting correctly, but you could tell that from your FT4 and FT3 - if you can get your FT3 tested!

I'm really not that sure about rT3. As you said, not much research has been done on it, and when you try to find something about it, it's all very vague. All I've really learnt is that it binds to T3 receptors in cells and stops the normal T3 binding to them. But it can't stay there forever, can it, or think of the state we'd all be in! How long it stays, is anybody's guess! I just know it takes at least 12 weeks on high doses of T3 to clear it - I took about 100/125 and it took me longer than 12 weeks until I thought it might be cleared, but I've never had it tested. But then, of course, I went back onto NDT and the whole thing happened all over again! Nobody told me that could happen.

I am sure, though that TT3 includes FT3, bound T3 and rT3. And TT4 includes FT4 and bound T4. And from there, some people go on to insist it also includes rT4! But, of course, there's no such thing because there isn't the mechanism for making it. And I've had many an arguement about that!

[humanbean]

Taking T3 only will suppress production of T4 to practically zero, assuming enough T3 is taken. Since T4 is the raw material for the production of reverse T3, then once T4 has disappeared then reverse T3 should very soon follow.

I've read that it takes about 12 weeks on T3 only to remove reverse T3.

You may find this site interesting : thyroidrt3.com/

[humanbean in reply to humanbean]

I should also have said, if you get rid of your reverse T3 then switch to either NDT or levo which contain T4, if the conditions that created the reverse T3 in the first place have not changed, then you will just create lots more.

[lucylocks]

Hi Humanbean

Many thanks for replying.

I am asking as my daughter who was diagnosed with ME/CFS by her G.P. but had Tsh of 4.7 range 0.35 - 4.7 and low in range T4 (sorry cannot remember level)

She has tried levo. and NDT but they did not help.

She has had longing standing low iron which she takes iron supplements along with Vit D B12 B-comlex, Selium and Omega 3

Her Adrenal Saliva tests showed extremely low a.m. and lunchtime cortisol and high afternoon and evening cortisol so she has been doing Paul Robinson's CMT3.

She found a good improvement at 45mcg. T3 so kept increasing in hope of full improvement but is now at 100mcg T3 with no further improvement.

I am going to order a T3 test and wondered if I should get ordered the reverse T3 as well.

Her temp. is still a little on the low side and B.P. is normal, she is not suffering any over HYPER symptoms.

I am reading through the link you kindly supplied for further advice and was wondering should she now reduce T3 or changed onto NDT.

[humanbean in reply to lucylocks]

How long has she been on T3 only? You say she has no hyper symptoms, but don't mention if she has any remaining hypo symptoms apart from low temp. If she feels well (or at least better than before) on T3, why change meds at all?

Having low iron will really mess up thyroid, and possibly adrenal function too (although I'm not sure about that). What kind of iron does she take, how much, and does she take it with vitamin C? It's supposed to help with absorption. Going gluten-free could help iron absorption too.

[lucylocks in reply to humanbean]

Hi

Yes she does feel better than she did, she has been riding her bicycle some days which would have been unheard of before starting T3. and doing more in general.

She has been taking it for about 4 months now.

She takes Ferrous fumerate 3 times a day with Vit C and she is also gluten free as she has celiac disease.

She increased her dose to 100mcg. 2 weeks ago. This last week she has gone down hill a bit, feeling more fatigued and getting insomnia again and feeling low.

She takes Ferrous fumerate 3 times a day with Vit C. Her ferritin at her last test had risen from 16 to 40, so still very low.

She is also gluten free as she has celiac disease.

Do you think the increase is too much as she has felt worse on the 100mcg. but as I said she has no symptoms of hyper.

Thank you browny

[Clutter in reply to lucylocks]

Browny, if your daughter feels worse after increasing to 100mcg she should go back to her previous dose. A FT3 test will show whether she is overmedicated which can cause fatigue as well as undermedication.

4 months off T4 should have cleared any build up of T4 and rT3.

[lucylocks in reply to Clutter]

Many thanks Clutter for replying.

I am going to send for a T3 test for her to see what is going on, she seems to think that as she has no palpitations or jitteriness that she is not over medicated, but as you say the fatigue can be a symptom of hypo. and hyper

[humanbean in reply to lucylocks]

Make sure there is a 24 hour gap between testing and the previous dose of T3. Do the testing having fasted for 10 - 12 hours, apart from water. Do the test first thing in the morning.

From now on always try to stick as closely as possible to these conditions to maximise the chances of making sensible comparisons between tests.

[lucylocks in reply to humanbean]

Many thanks, very much appreciate your advice.

[greygoose in reply to lucylocks]

Browny, there are lots of other vitamins and minerals that she could experiment with. As she's taking vit D3, adding some magnesium and zinc would probably help. Then there's boron, and vit A and vit E. She might not get tested for all those, but she could try a little and see how she feels on them. It's not just about hormones.

[lucylocks in reply to greygoose]

Many thanks Greygoose,

She has tried magnesium before but some types make her feel really sickly, I wonder if the magnesium spray oil would help.

I think she has just bought a multi vit. but not sure how much A and E is in it, I will check with her later today.

[greygoose in reply to lucylocks]

Probably not enough to help anything. Multi-vits are just for maintenance - if that.

There are several different types of magnesium, has she tried them all? The magnesium spray suits some people but it is messy. Has she tried adding Epsom salts to her bath and soaking for half an hour? Very relaxing, and the magnesium is absorbed through the skin.

[lucylocks in reply to greygoose]

Not sure which magnesium she has tried but I remember even in her teens she tried Magnesium O.K. for her PMT and she threw up half an hour later.

I will get her some Epsom salts and check out other mag. supplements.

Thank you for replying.

[greygoose in reply to lucylocks]

You're welcome.