Thyroid hormons T4/T3, someone else taking it for CFS/ME?

[Sing]

I meant the T3 isn't helping much.... Addressing WHY you have high RT3 should be your main goal at this point. Again it sounds like you have adrenal issues and I would HIGHLY recommend a diurnal cortisol kit.

-Taking T4 will only exacerbate problems if you have RT3 problems.
-T4 will convert to T3 or RT3
-Taking ENOUGH T3 will suppress TSH so that your body stops producing it's own T4
-Once there is no/low T4, there will be no/low RT3 and the T3 can do its job

Does T4 inevitably convert to either T3 or RT3, or can it just hang around as T4 then just drift uselessly away?

 

[Gondwanaland]

Does T4 inevitably convert to either T3 or RT3, or can it just hang around as T4 then just drift uselessly away?

http://www.tiredthyroid.com/rt3-7.html
http://www.tiredthyroid.com/rt3.html and links therein

In a nutshell: there are T4 receptors in the body

 

[CFS_for_19_years]

yeah I got a pill cutter but it's nowhere near sharp enough so I'm gonna try and find one of my mom's exacto knives...

I guess at these small doses it's not too ultra-important

My Cytomel tablets are 5mcg. Even with a really good pill cutter it is difficult to get it divided into quarters. Now I'm using a digital scale. I weighed 10 tablets at the same time and divided by 10 just to be sure I was getting an accurate weight for one tablet (150mg). Now I chop up a tablet in several pieces and weigh out the amount I want.

Here is the pill cutter that my HMO hands out for free from the pharmacy. I've found it to be the best of all the pill cutters I've used but the blade is hardly ever centered correctly. Even if you can get it centered pills have a tendency to crumble.
https://www.amazon.com/Apex-Deluxe-Pill-Splitter-splitter/dp/B000EGP5DC
https://www.ebay.com/itm/Apex-Deluxe-Pill-Splitter-1-Each/331715320788

This is the only scale I've ever used:
https://www.amazon.com/Smart-Weigh-SWS600-Pocket-Digital/dp/B00GS8LWIW
https://www.ebay.com/itm/Smart-Weig...gital-Scale-600-x-0-1g-Black-New/182617069232

It has four different weight modes. One of the weight modes is much more sensitive than milligrams. I think it would weigh a particle that was barely visible. Use some sort of small container on the scale, then press TARE to automatically subtract the weight of the container, then start putting all the little bits of your pill in the container until you get the weight you want.

I was diagnosed with hypothyroidism. The first thing I noticed when starting T3 was cognitive - I felt more awake and slept a bit less. I also had fewer aches in my forearms. I might have even regained some strength in my quads so that it was easier to stand up.

I sometimes notice some warming or increased heart rate about 4 or 5 hours after my dose if it's on the high side.

 

[frozenborderline]

My Cytomel tablets are 5mcg. Even with a really good pill cutter it is difficult to get it divided into quarters. Now I'm using a digital scale. I weighed 10 tablets at the same time and divided by 10 just to be sure I was getting an accurate weight for one tablet (150mg). Now I chop up a tablet in several pieces and weigh out the amount I want.

Here is the pill cutter that my HMO hands out for free from the pharmacy. I've found it to be the best of all the pill cutters I've used but the blade is hardly ever centered correctly. Even if you can get it centered pills have a tendency to crumble.
https://www.amazon.com/Apex-Deluxe-Pill-Splitter-splitter/dp/B000EGP5DC
https://www.ebay.com/itm/Apex-Deluxe-Pill-Splitter-1-Each/331715320788

This is the only scale I've ever used:
https://www.amazon.com/Smart-Weigh-SWS600-Pocket-Digital/dp/B00GS8LWIW
https://www.ebay.com/itm/Smart-Weig...gital-Scale-600-x-0-1g-Black-New/182617069232

It has four different weight modes. One of the weight modes is much more sensitive than milligrams. I think it would weigh a particle that was barely visible. Use some sort of small container on the scale, then press TARE to automatically subtract the weight of the container, then start putting all the little bits of your pill in the container until you get the weight you want.

I was diagnosed with hypothyroidism. The first thing I noticed when starting T3 was cognitive - I felt more awake and slept a bit less. I also had fewer aches in my forearms. I might have even regained some strength in my quads so that it was easier to stand up.

I may try getting a lower dose of T3 tablets so I can cut even smaller doses

 

[pattismith]

Does T4 inevitably convert to either T3 or RT3, or can it just hang around as T4 then just drift uselessly away?

the three possibilities does exist and have been reported; T4 intake can increase T3 or rT3, or do nothing, depending on people.

 

[pattismith]

ADRENALS ADRENALS ADRENALS

I cant stress that enough. Thyroid and adrenals work in concert.

I could reasonably theorize that the T3 you take (which peaks after about an hour on empty stomach) would work with what cortisol you have BUT end up using it all up, resulting in your fatigue later.

Licorice Root may extend the life of cortisol, which could help... BUT I'm going to say again you should get a diurnal cortisol kit ASAP

Okay, it took me three months of experiments with T3 and cortisol and I finally realised that you were right!
My adrenals doesn't work properly, and I don't have enough cortisol.

When I first experimented T3, I got a quick relief of my symptoms for 8 hours, then it was fading even though I was taking another dose.

Then I started T3 x3/day and the positive effect only came back when I added cortisol....
And today I was struggling this morning, I was again the broken doll I am used to be now, no matter my T3 intake.
I took my cortisol dose at 12, and I got very quick relief! And it lasted....8 hours!

So I guess the positive effect I got from T3 the frst time lasted 8 hours not because T3 is decreasing in blood after 8 hours (which is right but wasn't the real cause), but because cortisol was probably all spent by T3 after 8 hours. this is why adding more T3 at that moment was useless!

So you were right, T3 needs cortisol to work and cotisol need T3 to work.

Thank you for the time you took to enlight me, it helped me even though it took some time

 

[Iritu1021]

the three possibilities does exist and have been reported; T4 intake can increase T3 or rT3, or do nothing, depending on people.

Interesting conversation, I will chime in on that. I don't think T4 ever does "nothing" - if it doesn't get converted, it actually competes with T3 for the cell entry creating a "relative T3 deficiency". However, the CNS system primarily uptakes T4 and converts it on its own so T4 is important for CNS health.

I believe that high doses of T3 are primarily effective because they stimulate an adrenal gland response - but over long term it takes tall on HPA and adrenals and T4 deprivation affects CNS. I've struggled with on/off T3 effect for several years - and later with long term effects of supra-physiological T3 doses - until I read Kenneth Blanchard's book "Functional Approach to Hypothyroidism" (which is a quick and easy read and I highly recommend it). Based on my own experience, I realized that Dr. Blanchard was right: even at 2.2 mcg of T3 (which is in 1/4 grain, the lowest dose of Armour) it's completely overdosed - especially if released into bloodstream all at once! The normal ratio of T4:T3 produced by the thyroid gland is 97:3, the rest of T3 is generated within the cells and not "dumped" on the body extracellularly.

The tiny amount of T3 that comes from thyroid naturally is enough to boost the adrenals and stimulate peripheral conversion without suppressing TSH. I now take 25 mcg of Levoxyl + 20 mg hydrocortisone (in divided doses) + 0.3 mcg slow release T3 and I feel much more stable on this combination than I ever felt on T3 or NDT. I hope I will be able to come off hydrocortisone in the near future as I hope my adrenals will recover from my years of "T3 abuse".

I get my T3 compounded but for those who are savvy with digital scales, one can buy slow release capsules and mix 2.5 mg of crushed Armour powder with Methacell powder which is sold on Amazon to make your own slow release capsules. (Armour is much easier to crush than Cytomel).

 

[pattismith]

Interesting conversation, I will chime in on that. I don't think T4 ever does "nothing" - if it doesn't get converted, it actually competes with T3 for the cell entry creating a "relative T3 deficiency". However, the CNS system primarily uptakes T4 and converts it on its own so T4 is important for CNS health.

I believe that high doses of T3 are primarily effective because they stimulate an adrenal gland response - but over long term it takes tall on HPA and adrenals and T4 deprivation affects CNS.

Do you have some scientific source about the SNC primarily uptaking T4?

I am not sure that T3 stimulates my adrenal: in fact, I only got a positive effect from my three times/day T3 trial when I added some prednisolone with it!

 

[Iritu1021]

Do you have some scientific source about the SNC primarily uptaking T4?

I am not sure that T3 stimulates my adrenal: in fact, I only got a positive effect from my three times/day T3 trial when I added some prednenolone with it!

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3978256/

Thyroid hormones (THs) are essential for fetal and post-natal nervous system development and also play an important role in the maintenance of adult brain function. Of the two major THs, T4 (3,5,3′,5′-tetraiodo-l-thyronine) is classically viewed as an pro-hormone that must be converted to T3 (3,5,3′-tri-iodo-l-thyronine) via tissue-level deiodinases for biological activity. THs primarily mediate their effects by binding to thyroid hormone receptor (TR) isoforms, predominantly TRα1 and TRβ1, which are expressed in different tissues and exhibit distinctive roles in endocrinology. Notably, the ability to respond to T4 and to T3 differs for the two TR isoforms, with TRα1 generally more responsive to T4 than TRβ1. TRα1 is also the most abundantly expressed TR isoform in the brain, encompassing 70–80% of all TR expression in this tissue. Conversion of T4 into T3 via deiodinase 2 in astrocytes has been classically viewed as critical for generating local T3 for neurons. However, deiodinase-deficient mice do not exhibit obvious defectives in brain development or function. Considering that TRα1 is well-established as the predominant isoform in brain, and that TRα1 responds to both T3 and T4, we suggest T4 may play a more active role in brain physiology than has been previously accepted.

As for T3 effect on cortisol - it's something I have observed in myself on more than one occasion both in plasma and salivary cortisol testing. Taking T3 always made my cortisol go high off the chart (without it runs low normal or too low).

I only use pregnenolone (or DHEA) whenever I overshoot on my hydrocortisone or thyroid and make myself too hyper. I find that it actually dampens cortisol/ T3 effect. I doubt much of pregnenolone gets converted to cortisol, at least not in my case. For me, it feels very similar to taking DHEA, which actually seems to have more of an opposing effect on cortisol - that's probably why it only seems to work as adrenal support in early stages of adrenal fatigue when cortisol still runs high.

 

[BadBadBear]

@pattismith - have you looked into Paul Robinson's circadian dosing protocol? People can often go completely off of hydrocortisone by adjusting the timing of their T3 dosing. I take a 4 AM dose of T3 to boost my morning cortisol output. It definitely affects adrenals.

Problem is, if adrenals are already dragging and low, T3 puts a demand on them and can make things worse. I could not tolerate T3 well at all when I was taking it at 6 AM in the morning.

After I started circadian dosing, I had to take it at 2:30 AM for a long, long time for the maximum adrenal boost and it has only been recently in the last year that I've had to move it later in the morning to around 4 AM because I was getting too much of a boost.

If you have not looked into CT3, I would highly recommend it! Makes a big difference for a lot of people.

 

[pattismith]

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3978256/

Thyroid hormones (THs) are essential for fetal and post-natal nervous system development and also play an important role in the maintenance of adult brain function. Of the two major THs, T4 (3,5,3′,5′-tetraiodo-l-thyronine) is classically viewed as an pro-hormone that must be converted to T3 (3,5,3′-tri-iodo-l-thyronine) via tissue-level deiodinases for biological activity. THs primarily mediate their effects by binding to thyroid hormone receptor (TR) isoforms, predominantly TRα1 and TRβ1, which are expressed in different tissues and exhibit distinctive roles in endocrinology. Notably, the ability to respond to T4 and to T3 differs for the two TR isoforms, with TRα1 generally more responsive to T4 than TRβ1. TRα1 is also the most abundantly expressed TR isoform in the brain, encompassing 70–80% of all TR expression in this tissue. Conversion of T4 into T3 via deiodinase 2 in astrocytes has been classically viewed as critical for generating local T3 for neurons. However, deiodinase-deficient mice do not exhibit obvious defectives in brain development or function. Considering that TRα1 is well-established as the predominant isoform in brain, and that TRα1 responds to both T3 and T4, we suggest T4 may play a more active role in brain physiology than has been previously accepted.

As for T3 effect on cortisol - it's something I have observed in myself on more than one occasion both in plasma and salivary cortisol testing. Taking T3 always made my cortisol go high off the chart (without it runs low normal or too low).

I only use pregnenolone (or DHEA) whenever I overshoot on my hydrocortisone or thyroid and make myself too hyper. I find that it actually dampens cortisol/ T3 effect. I doubt much of pregnenolone gets converted to cortisol, at least not in my case. For me, it feels very similar to taking DHEA, which actually seems to have more of an opposing effect on cortisol - that's probably why it only seems to work as adrenal support in early stages of adrenal fatigue when cortisol still runs high.

Oh this is really interesting,

First I apologize, I didn't mean Pregnenolone, but Prednisolone;

Second: so you didn't mean that T4 uptake by brain cells is bigger than T3 uptake, but you were talking about T4 affinity to TRα1 that is stronger than T3 affinity.

@BadBadBear i will have a look at this protocol!

 

[bertiedog]

Then I started T3 x3/day and the positive effect only came back when I added cortisol..

I did think that everybody was aware that in order for any thyroid medication to work one had to have sufficient cortisol. If one doesn't have either good adrenal function or alternatively taken a dose of hydrocortisone or Prednisolone one can feel worse as it will convert to ReverseT3.

It's probably the missing key for so many people who actually need thyroid support but don't get any benefit or feel worse if they do get round to try any thyroid med, be it T4 or T3. Having said that I am not convinced many GPs know this!

Because I am steroid dependent and very aware when my cortisol is all used up even if I try and add just 6 mcg T3 as a top up evening dose, I can feel quite horrible but if I add just 2.5mg h/c within 20 minutes I will start to feel much better both in my brain and especially my legs. Energy will return for a short period of time which makes a big difference to how I am feeling. However by 11 pm I will become very tired and not feel great and know I just have to go to bed to sleep and wait for my next dose of steroid/thyroid medication which is usually around 5 am. I naturally wake up for this and usually go back to sleep after I have taken it (together with a small amount of thyroxine). There is no question the adrenals are so often overlooked.

Pam

 

[BadBadBear]

@bertiedog I have the same thing happen, my body wakes me up for my 4:30 am dose of T3 then I can go back to sleep. I am currently trying to add T4 and also take some then.

I am finding T4 pretty stimulating at the moment and have to multi dose it during the day. Very perplexing as so much is made of it having a long half life. Wonder if I am just using it up quickly??

 

[Iritu1021]

Oh this is really interesting,

First I apologize, I didn't mean Pregnenolone, but Prednisolone;

Second: so you didn't mean that T4 uptake by brain cells is bigger than T3 uptake, but you were talking about T4 affinity to TRα1 that is stronger than T3 affinity.

@BadBadBear i will have a look at this protocol!

Yes, that would be a better way to summarize this particular study, I only vaguely remembered it at the time of writing my post. My beliefs on T4 are more experiential. I am aware that there are few people out there like Paul Robinson who seem to be able to adjust and live on T3 alone - but definitely not me. When my T4 went really low due to TSH suppression on high T3 doses, my nervous system was screaming S.O.S. on top of its lungs.

I think there is probably more to it than different receptor binding, there is also some building evidence that T4 might function as a co-transmitter for norepinephrine.

I think not only T3 but T4 is also affected by timing of the day. I react differently if I take it before bed or in the morning. Initially, I could only tolerate it at bedtime. Blanchard also writes in his book that everyone has their optimal timing for taking T4 and T3 and it varies from person to person. Circadian effect on the levels of ACTH and TSH seems like the most logical explanation.

One interesting paradox I noted about taking micro-doses of T3 is that when used on its own (without supplemental T4), is that it would make my TSH go up rather than down.

 

[BadBadBear]

When my T4 went really low due to TSH suppression on high T3 doses, my nervous system was screaming S.O.S. on top of its lungs.

Do you know what exactly happens when T4 is suppressed, @Iritu1021 ? For ex. if I am taking T3 and it's suppressing my T4, but I'm also taking a large dose of T4, where does it go? Does it get metabolized and immediately excreted or what is happening there? Is it all bound up and in circulation but not bioavailable? I have never been able to find this information.

I am currently on 12 mcg T3 total daily and 100 mcg T4. My last blood test, when I was on a smaller amount of T4 and a higher amount of T3, showed I had suppressed T4.

I am trying to titrate my meds to the optimal amount where I have both hormones in a good concentration. I am curious to see my next labs to see if the suppression is any better. And if not, the question is whether to raise T4 or lower T3 again.

I just don't understand the biomechanics of T4 suppression enough to know what is best.

FWIW, I cannot tolerate T4 at night! Its so stimulating it keeps me awake.

 

[Iritu1021]

Do you know what exactly happens when T4 is suppressed, @Iritu1021 ? For ex. if I am taking T3 and it's suppressing my T4, but I'm also taking a large dose of T4, where does it go? Does it get metabolized and immediately excreted or what is happening there? Is it all bound up and in circulation but not bioavailable? I have never been able to find this information.

I am currently on 12 mcg T3 total daily and 100 mcg T4. My last blood test, when I was on a smaller amount of T4 and a higher amount of T3, showed I had suppressed T4.

I am trying to titrate my meds to the optimal amount where I have both hormones in a good concentration. I am curious to see my next labs to see if the suppression is any better. And if not, the question is whether to raise T4 or lower T3 again.

I just don't understand the biomechanics of T4 suppression enough to know what is best.

FWIW, I cannot tolerate T4 at night! Its so stimulating it keeps me awake.

The amount of T3 appears to affect how quickly you use up serum T4 stores. Blanchard wrote that he preferred giving tiny doses of T3 in the form of dessicated thyroid because adding even these micro-doses of T3 caused his patients to burn through T4 faster. Some of it is probably due to increased tissue utilization, some due to increased excretion - both would be found in the hypermetabolic state associated with high T3 intake.

My learning curve about T3 over the years can be summed up as "less is more". Blanchard described the same observation he made over 25 years of endocrinology practice - that if someone takes T3, gets better on it initially for a few days or weeks and then gets worse, it is almost always because they took too much to begin with, not because they didn't take enough.

If you were ever to test your blood levels right after taking even a small dose of immediate release T3, you will see that the blood peak concentrations 1-2 hours after dose are often similar to those of someone with severe Grave's disease. There is nothing physiologic about taking doses of T3 that are currently being prescribed. The body must work very hard to adopt to such high levels, and if someone doesn't have an appropriate hypothalamic response, they usually will not be able to adopt. Most of popular alternative thyroid teachings that one will find online today (STTM and such) were not designed for CFS population, at least not for those of us with severe illness. Dr. Blanchard looked at the issue from a completely different, unorthodox perspective and because of that he was able to treat successfully lots of people who either failed to get better or felt worse on conventional doses of T3 and NDT.

My personal theory is that the body's response to high T3 may be upregulation of T1AM production (which is essentially an anti-T3 hormone that I explored on my blog and other threads). So when T3 levels drop a few hours later, you end up left with higher than normal T1AM and that makes you feel like you are T3 deficient (when in fact you've got too much of it). Taking T4 in these situations makes things even worse as it might further drive up T1AM production. An acute excess of T1AM can drive up glutamate production and create a feeling of hyperexcitation that you might be referring to.

 

[adambeyoncelowe]

I find 60mcg NDT every other day seems to help. But when I was taking 25mcg levo + 30mcg NDT, I got jittery.

My TSH was 3.5 a few years ago, then 3.4 when I got my ME diagnosis. Now, after a bit of NDT, it's like this:

Thyroid Function:
THYROID STIMULATING HORMONE 1.87 mIU/L 0.27-4.20
FREE THYROXINE 16.7 pmol/L 12.00-22.00
TOTAL THYROXINE(T4) 91.7 nmol/L 59.00-154.00
FREE T3 4.15 pmol/L 3.10-6.80
THYROGLOBULIN ANTIBODY 13.800 IU/mL 0.00-115.00
THYROID PEROXIDASE ANTIBODIES 25.7 IU/mL 0.00-34.00

Does anything look amiss, besides the higher than ideal TSH?

 

[pattismith]

I did think that everybody was aware that in order for any thyroid medication to work one had to have sufficient cortisol. If one doesn't have either good adrenal function or alternatively taken a dose of hydrocortisone or Prednisolone one can feel worse as it will convert to ReverseT3.

It's probably the missing key for so many people who actually need thyroid support but don't get any benefit or feel worse if they do get round to try any thyroid med, be it T4 or T3. Having said that I am not convinced many GPs know this!

Because I am steroid dependent and very aware when my cortisol is all used up even if I try and add just 6 mcg T3 as a top up evening dose, I can feel quite horrible but if I add just 2.5mg h/c within 20 minutes I will start to feel much better both in my brain and especially my legs. Energy will return for a short period of time which makes a big difference to how I am feeling. However by 11 pm I will become very tired and not feel great and know I just have to go to bed to sleep and wait for my next dose of steroid/thyroid medication which is usually around 5 am. I naturally wake up for this and usually go back to sleep after I have taken it (together with a small amount of thyroxine). There is no question the adrenals are so often overlooked.

Pam

Hello Pam, it's interesting how we experience the same conjugated need for T3 and corticosteroids.
Did you try to take T3 three times per day (every 8 hours), with your usual dose of corticosteroid?

I don't feel any more weakness if I do this way, and if I feel bad, i just have to add some cortico, and i have a quick effect too.

I just started to introduce again some T4 to my protocol, I hope it won't convert to rT3, I will feel it soon if it does.
T3 stimulates D1 and D1 clears rT3 , so I hope I take enough T3 to solve the problem.

 

[bertiedog]

Hello Pam, it's interesting how we experience the same conjugated need for T3 and corticosteroids.
Did you try to take T3 three times per day (every 8 hours), with your usual dose of corticosteroid?

I don't feel any more weakness if I do this way, and if I feel bad, i just have to add some cortico, and i have a quick effect too.

I just started to introduce again some T4 to my protocol, I hope it won't convert to rT3, I will feel it soon if it does.
T3 stimulates D1 and D1 clears rT3 , so I hope I take enough T3 to solve the problem.

I am back to my usual dessicated thyroid medication of 2 grains daily plus 25 mcg thyroxine. I was only on T3 for a while several years ago after an extremely stressful period where I had to stop all thyroid meds. After a couple of weeks of no meds I was getting completely hypothyroid but still couldn't tolerate any T4 so had to gradually build up T3 taking it probably 3 times daily until after a couple of months I was ok with my usual dessicated. In the winter I have been known to take around 10 mcg T3 as a top up early evening but this is rare.

For me T3 always felt like I was missing something and when 18 months ago an NHS Endo told me I was over medicated (which was rubbish) he told me to stop the 25 mcg thyroxine. By the 2nd day of stopping I just could tell my body was missing it even though they say it is inactive. I noticed it when walking my dog inn the afternoon, I just didn't have my usual stamina. Within a month of being off just the 25 mcg T4 but still on the 2 grains nearly all of my old symptoms had come back but especially panic attacks when out walking and I couldn't keep my blood sugar stable when walking or doing anything physical. I had lots more body aches and pain plus my sleep was terrible. All in all it was a horrible experience that took months to get over once I got back on it.

BTW It was reflected in my blood test results. T4 before stopping was 15.4 but just 7 weeks off this (but still on the 2 grains) dropped to 7. I was delighted that the test just showed how I was feeling but the Endo said that there was no way just stopping that small amount could do this to me. Of course he is wrong but it goes to show for some of us what a tiny amount of T4 can do for us. On its own anything more than 25 mcg thyroxine makes me toxic but as an add on to the 2 grains its perfect for me. Actually I am extremely sensitive to medication and some supplements so its no surprise to me that I reacted in the way I did.

One reason that I have to take the 6 mg Prednisolone is my need for thyroid hormone. I wouldn't be able to take thyroid meds otherwise because I only make a tiny amount of my own cortisol.

Glad you have found something that helps you too.

Pam

 

[Iritu1021]

@adambeyoncelowe - I could not add any T4, not even the smallest doses when my TSH was <1.5. It gave me a different type of very unpleasant stimulation, different than T3 - like some unpleasant coffee or stimulant overdose with a depressive overtone to it, and it made all my various infections and autoimmunities flare up.

Also, T3 and T4 are measured in micrograms, NDT is measured in miligrams. I assume you were taking 30 mgs of NDT or about 1/2 grain. If Ken Blanchard was still alive, he'd probably tell you that you took way too much NDT. Had you taken 2.5 -5.0 mg instead of 30 mg, you might have gotten a much better mileage out of your 25 mcg of levothyroxine and avoided the jittery feeling - while still getting all the benefit of T3 that you needed.

Unfortunately, I've been informed by my compounding pharmacy that USP thyroid is no longer available so I can no longer compound micro-doses of NDT anymore. It does seem that 2.5 mg of Armour has a slightly better effect on me than the equivalent 0.3 mcg of pure T3 but in the end they both do the job they are supposed to do.

I want to stress the fact that I'm not using such tiny doses because I'm extra-sensitive to meds. In fact, I'm hardly sensitive to any medications at all anymore and after many years I can even drink alcohol again in limited amount. I use such low doses of T3 because I find them to have a more potent, better lasting and much more stable effect on me than anything over 1 mcg, and it seems as if T3 has a biphasic mode of action (<1 mcg and >1 mcg) and that immediate release and slow release affect the body in very different ways.

I'm also now learning to adjust my dose depending on my monthly cycle. During my follicular phase I feel pretty much normal, during luteal phase I still tend to get tired (but not like in the past when I'd completely fall apart). In his book Blanchard recommends decreasing T3 and increasing T4 by 10-20% a week before the period to prevent PMS.

When I tried stopping my thyroid hormone a couple months ago - to check if I really needed it, I began to slip right back into severe CFS and all my chronic viral infections seemed to begin to reactivate. I went back on T4 and got better within a few weeks.