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Thyroid UK
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I was hoping someone could give some advice on pooling? I've temporarily stopped my Nature-Throid meds while I try and sort this out, but could really use some advice. I don't know the best way to deal with this or how long it might be a problem.

I had a severe ME diagnosis, but was diagnosed by both Dr M and Dr P as having a thyroid prob. I am under treatment from Dr P. I had reached the dizzy heights of 45mgs of Nature Throid, having previously got to 3 Nutri-Thyroid before deciding to switch.

My GP knows about this, and is very supportive, telling me to see the NDT as supplements (I think she feels her hands are tied) as they were helping me, and we're aiming to get me on my feet enough to manage getting to see an Endo as soon as poss. I had been on my feet far more and able to do some short walking and yoga, which is a great improvement from being bedbound & hardly able to sit up.

Last week I started having bad panic attacks so my GP agreed to retest my thyroid and my iron. She didn't think my NDT dose was high enough for it to be that, per se, causing the panic attacks. However, it turns out my ferritin had sunk to 15 from 70 in January, so that clearly is a big problem... (Heavy periods). I'm presuming that this is a factor in why I started having panic attacks etc, from the thyroid stopping working in the cells and pooling???

I also did a Genova private test to see my T3 and rT3. Previously my T3 had been low in range. It had gone up to high in range, as had my rT3. Does that confirm the pooling? It also said I had TPO antibodies out of range at 42 (<35) and wrote in the commentary box "Probable auto-immune thyroid disease".

Can anyone tell me the best way of dealing with this - should I stop taking the Throid for a while while I build up the iron? (Even if it means going back to being bedbound?) How long can pooling take to reduce (if that's what it is?). I know it's going to take at least a month of 2x iron tabs and iron rich diet to get my ferritin up 30 points (have done this before).

Any advice would be really appreciated.

7 Replies

Hi Sirone - I think low ferritin and/or cortisol can cause rT3 to build up. I know some people go on T3 only to clear rT3, but I think I managed to get rid of it on a low dose of NDT, by raising my ferritin level and adopting CT3M.

Have you had a 24 adrenal saliva test done? This would highlight any cortisol problems and could indicate I the CT3M might be s unit able approach for you.

In your position, I would probably get the iron levels up ASAP (don't forget to take it well away from NDT) and do the saliva test.

Ar you able to post your actual test results including the rT3? Xx


Are you a member of the RT3 yahoo group, they might be able to give you some advice



Yes, I've just joined the group , thanks. Someone on there suggested I need T3 "to clear the receptors..." I don't really understand any of this, so it's a steep learning curve! All input gratefully received as I try to get my head around what might be happening.

Dr P did originally want to start me on T3, but as I'd already started on NDT with Dr M, he built around that. Maybe I need to switch...

My last test results last week were (after 2+ months on NDT):

TSH: 2.4 mU/L (0.3-5.5)

FT4: 14 pmol/L (10-22)

FT3: 5.82 pmol/L (2.8-6.5) (Gone up from low in range)

RT3: 0.41pmol/L (0.14-0.54)

Ratio RT3/T3 = 14 (I think)

TPO: 42 (0-35)

TgAB: 20 (0-40)

Ferritin: 15.6 ug/L (20-200, I think)

Transferrin Satn: 4% (15%-45%)

Serum Iron: 4 umol (LOW - no range)

Serum TIBC: 89.7 umol/L (LOW - no range)

Previous, from a few months ago:

B12: 834 ng/L (HIGH - no range)

Vit D: 48.7 (>50)

Others like folate and magnesium were in range.

I really took my eye off the ball with the iron, as I was feeling so much better and stronger on the NDT, I didn't realise my iron was dropping so much. :(

I think it might be in part that I switched to an anti-candida diet, which was much more limited. I stopped eating things like fruit, (apricots), potatoes and pulses/beans which I used to use to help with the iron intake. I was taking things like Floravit and Spatone, I guess it's just not strong enough and I need to keep on the iron tablets.


Thanks Claire - did it take you long to get rid of the rT3? btw I don't know what 'adopting CT3M' is??!

I had my cortisol tested earlier in the year. GP tested 24 hr urine, and it came back about 90 which she said was mid-range. The 24 hr salivary test just showed a slightly raised first am cortisol. Total daily cortisol: 38.2 (21-41).

I took some adrenal glandulars support, but couldn't tolerate more than one tablet. It made me very wired, with aggressive/angry feelings. Dr P concluded that any adrenal problem was probably secondary to the main thyroid illness. I take 2g of vit C and drink Holy Basil tea. (And do a lot of meditation!)


Thanks Heloise, I'm starting to understand it a little.

No idea what to do about my medication. Maybe I should just take some Nutri-Thyroid for a few days, but I fear even that may add to the problem, if it's boosting my T4 production...?

What I don't get is how I would know if just building up my iron (from tablets) is enough to start clearing the rT3?

If I asked my GP to help organise a private test for rT3 and T3 in, say, 3 weeks, would that be enough time to see if the pooling had reduced? The Genova full thyroid panel blood test is quite expensive, so I don't want to do it within an unrealistic time frame.



Have you had any luck with sorting out you're RT3 problem?

I don't know if I've got it but someone said my pounding heart suggests I do have it and it's likely been caused by high cortisol as my saliva test came back with three highs.

I am on combo t4 t3.

I agree Genova are expensive when you can only get ft3 and RT3 tested as a whole lot of tests as they don't test separately!!!!

Can you help ir advise me at all please

Rose 🌹


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