Are there any articles on the subject of absorption differences between NDT and thyroxine/liothyronine?
I am reviewing my NDT blood test results against my levo/combined T3 and T4 results. The difference is astonishing. On NDT I can get into the correct T3 and T4 ranges with ease; any adjustment in dosage is quickly visible in the blood test results year on year. On my current combined T4/T3 protocol under the Kingston Hospital endocrinologist, my FT4/FT3 levels barely shift despite an increase in both doses over the past 2 years. TSH remains suppressed on both types of treatment and appears the only thing the endo looks at.
Sorry to keep posting, but I'm anxious about my next endo appointment in a week's time and am trying to cover all the angles that might come up. Last year, someone on this fabulous forum suggested I may have an absorption problem, and indeed I have had H Pylori a number of times plus believe I have low stomach acid (the GP literally laughed at me when I mentioned it).
I've had a look around and can't find anything on absorption differences between NDT and synthetic thyroid medication, so thought I would ask all you super people.
x Angela
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Agree, I'm really not sure why my T3 and T4 are well into range on NDT and I feel much better, compared to bumping along the bottom on synthetics. I've scanned the post by tattybogle on this issue and it appears to be the case that "NDT T3 is mostly protein bound and this causes delay in uptake until the protein thyroglobulin has been almost entirely degraded to release the T3 for uptake in cells", so slower release and delayed uptake seem to be key here.
Yes, I saw Dr Peatfield around 10 years ago and slowly took the NDT route after the GP couldn't get my TSH under control (it was always too high) and my thyroxine dose hit 250mcg. My GP has never been on board and in 2020, withheld my medical exemption certificate saying I was not on approved meds, so I relented and agreed to try the conventional route. The endo has me on combined T4/T3 synthetic but I am very poorly with very low levels of FT3/4. Sadly they appear obsessed with raising my TSH which is around 0.04, praising the excellent result when it goes up while ignoring my hypo symtoms and low levels of T3/T4. They think they may reduce my dose on my next appointment if my TSH hasn't increased....
I am trying t3/4 combo with local Endo having been on NDT for over 10 years self treating.
Our local NHS endo, who I have only seen once so far, seems only to treat the TSH and my TSH falls very low as soon as any type of t3 is added.
On t3/4 combo my TSH has risen to 0.05 and t3/4 both dropped a point or 2 . I have no energy and fall asleep every afternoon if I sit down! Endo happy with my results and not bothered about symptoms. dry skin, hair loss, lack of energy, constipation, balance issues.
I have added a tiny bit extra levo (against the Endos wishes ) constipation and balance issues have resolved and skin is less dry but I still lack energy.
Bloods due in another 4 weeks. No Endo appointment received yet.
I will consider going back on NDT after these new bloods if endo is still deaf to my symptoms.
Your case is identical to mine. Poorly on levo, tried NDT for around 7 years, came back into the NHS fold after persistent bullying by my GP (who BTW told me I will need to come off thyroxine and replace it with thyroid suppressants for my overactive thyroid....). When an ultrasound showed my 'ragged' thyroid gland (the words of the chap doing the scan) with cysts etc, and after meeting the endo at Kingston, I was put on synthetic T3/T4 combo and it's been a disaster. Next week I'm two years into the treatment and need to have a 'constructive' conversation with the endo as to the way forward. I just want to go back on NDT and be well again!
Awww, thank you so much and truly good for you that you are taking more assertive action than I am! But I can't take it anymore, this is such a cruel sytem. I'm compiling my results history. On NDT I'm in the top third of the FT3/FT4 ranges, on synthetic combo treatment, the highest I've got is in the bottom quartile! And the TSH that they love so much has changed by barely anything. Thanks endos and GP for completely ruining my quality of life! Sorry if I sound fed up and thank you for your support Angela
You are ill. The treatment approach has not worked. It has made you worse.
If the medic praises your tsh, perhaps you could drag their attention away from tge numbers (like in a bodily way, big shift in your chair, sitting upright or something) and say - I've tried this for two years. Why am I still ill? Can you explain because I don't understand?
Tell them your quality of life has gone drastically downhill on this treatment. You were much better before, so you can compare.
And how do they see your health improving from here onwards? Because on the current treatment you are unable to manage.
Can you take someone with you perhaps?
Sorry if the suggestions aren't helpful, please feel free to ignore them. Your message really struck me so I had to respond.
I'm going to be asking my gp (again) for an increase from 75mcg to 100mcg levo once my vits etc. are better and I'm facing a similar conversation.
Thank you SO MUCH for your reply, brought a tear to my eye, I so appreciate your support. I honestly don't know what I would have done without this forum at this stage of my journey. And I wish you so much luck and support with your GP conversation; I am horrified by their lack of knowledge of how the thyroid works alongside the power they hold over our lives and health outcomes.
I will definitely use that form of words (and stature if I don't start crying!). I am taking my husband with me to back up what I am saying about my poor quality of life these past two years. I pride myself on fighting my own battles, but this is one I feel I need some help with!
Thank you again for your support and best of luck with your 'conversation' when it comes around
I've been pondering the comparability between doses this afternoon and am a little confused. I'm on 30mcg T3 and 150mcg thyroxine. I'm trying to make sense of my most recent NDT dose but don't have the old container. I have a note that it was 1.25 grain, twice a day - morning and night. The note also says each tablet was 113.75mg = T3 15.75mcg, T4 66.5mcg per tablet, taken twice a day. Dr Panos the endo tells me that 1 grain = 100mcg levo. So I'm confused... Will need to dig out old orders...
Thank you so much tattybogle for all the support you give on this forum, from the bottom of my heart, it's hard for you to appreciate how much you help people like me.
I have dug out my last container of NDT that I was taking until January 2021 (which I kept in case something like this happened). It is Nature-Throid 1.75grain (113.75mg) - this is the information on the front of the label. On the back it says T3 15.75mcg, T4 66.5mcg. I took one in the morning and one at bedtime for around 6 years. When I was on thyroxine only under the GP prior to moving to NDT, I was on 250mcg thyroxine with a high TSH.
My TSH, FT3 and FT4 levels in blood tests over the NDT years averaged TSH 0.005, FT4 20.8, FT3 6.03, and FT3 percentage of range 79.3%. I had much better health and sense of wellness on that dose, which seemed to be the level that suited me.
Now on combined T4/T3 therapy for two years of, most recently T3 30mcg and Thyroxine 150mcg (they have slowly increased the levels), blood tests average TSH 0.03, FT4 12.3, FT3 3.3 and FT3 percentage of range 15.3%. I have much worse brain fog, slumps between T3 doses and my brain seems unable to join up information anymore. They have suggested it could be menopause, but I was in menopause for two years before they put me on combined T4/T3.
I find myself wondering if it is absorption issues on the synthetic medication or simply the dose is too low, or both. They refuse to commit to a single brand so this changes. At a loss to know how to deal with the endo next Thursday.
Yes, i think It does look like your absorption of synthetic T3 T4 may not be as good as it was of NDT .. a direct equivalent to your previous 3 and a half grains daily NDT dose 'ought' to be 31.5mcg synthetic T3 + 133mcg synthetic T4 daily .... you are currently taking 17mcg more T4 than that , and only marginally less T3 (1.5mcg less)..... but this dose is clearly giving you much lower fT3 / fT4 levels and consequently a slightly higher TSH.
Have they tried increasing your synthetic T4/T3 doses enough to give you the same sort of fT3 / fT4 numbers where you felt well on 3.5 grains NDT ?
Alexandra O'Sullivan1, Ronald Brazg2, Barry Horowitz3, Gary Pepper4, Hong Li5, Oscar Antunez‐Flores6, William Ferguson*1, Antonio Bianco7
1AbbVie, Inc., USA,2Rainier Clinical Research Center, USA,3Metabolic Research Institute, Inc., USA,4Palm Beach Diabetes and Endocrine Specialists, P.A., USA,5AbbVie, Inc., USA,6AbbVie, Inc., USA,7Section of Adult and Pediatric Endocrinology and Metabolism, University of Chicago, USA
Objective: A phase 2 dose‐conversion study (ARCH) which was recently completed, included an objective to develop a methodology for switching patients from LT4 to Armour Thyroid (ATH).
Methods: ARCH participants were required to be treated with LT4 for at least 12 months and have an in‐range TSH (0.45–4.12 mIU/L) at screening. Participants were randomized to receive their current dose of LT4 or a prespecified dose of ATH calculated based on a dose‐conversion chart (USP Drug Information 2000). The USP states that 1 grain of ATH is equivalent to 100 mcg of LT4, which led us to create a dose conversion chart of 11 doses for the ARCH study. Results were analyzed for participants who completed the Titration Period (18‐36 weeks) with an in‐range TSH (Titration Responders). Dose‐conversion results were analyzed using regression best‐fit to investigate the dose at the end of titration compared with the dose prior to randomization.
Results: For the LT4 participants, the slope of the regression line (the regression slope = 1.0008 [R2 = 0.8949]) was nearly identical to the slope of the identity line, indicating that most participants' pre‐randomization dose matched their post‐randomization dose (70.2%); 8.3% of participants required an up‐titration and 20.7% of participants required a down‐titration. For the ATH participants, the slope of the regression line (the regression slope = 0.0118 [R2 = 0.8249]) was greater than the slope of the identity line (y = 0.0100), indicating that many patients who were switched to ATH required titrations to a higher dose (48.6%) than that recommended by the USP; 1.8% of participants required a down‐titration and 47.7% did not require titrations. Of the ATH participants not needing titrations, ∼78% had a pre‐randomization dose of 88 mcg or lower. The difference in the titration profiles between the LT4 and ATH participants was statistically significant (p < 0.0001).
Discussion: Based on these data, it is likely that dosing of ATH using the USP 2000 guidance is sub‐optimal, and may lead to underdosing of patients. The ARCH study did not meet the primary efficacy endpoint of non‐inferiority of ATH compared with LT4, and this may have been significantly impacted by the initial dosing of ATH."
4. Discussion ~ " ....... In this study, we observed that, among forum participants, 81% perceived as moderate-to-major the effectiveness of DTE therapy. In this regard, our results are similar to previous survey-based studies reporting higher median satisfaction; lower reports of problems with weight management, fatigue, mood, or memory [8]; and an overall positive drug effect in individuals treated with DTE, compared to those taking LT4 or LT4 + LT3 [26]. "
Thank you so much tattybogle for going to so much trouble to provide all of that, I very much appreciate it and hope to add it to my points to make on Thursday.
"Have they tried increasing your synthetic T4/T3 doses enough to give you the same sort of fT3 / fT4 numbers where you felt well on 3.5 grains NDT ?"
They are only interested in reducing the TSH. Blood tests are 6 months apart, and as I've said in a previous post, I now pay for my blood tests as the hospital loses half of them then I have an endo appointment without bloods to discuss. At my last appointment in September, my T4 and T3 numbers had a minor increase (from 10.2 to 11.2 and 2.6 to 3.4 respectively). The endo kept my dose the same due to the TSH becoming slightly more suppressed. He warned me they may reduce my dose at the next appointment (the one this Thursday, hence my anxiety) if my TSH doesn't improve.
I raised concerns a year ago that I seemed to be on a similar dose of synthetics to my previous NDT but getting not even a quarter of the results. I received the following response from the endo: "Generally, 1 grain is 60mcg and contains 38mcg of T4 and 9mcg of T3. Some brands have 65mcg. Equivalence charts show that 1 grain of NDT has the approximate equivalence of taking 100mcg of levothyroxine... I think it is encouraging and safe that the TSH is not suppressed any more and we work at increasing the doses of T4 and T3 gradually aiming for fT4 levels near the high teens and fT3 levels within the normal levels." My TSH one year ago had gone from 0.02 to 0.05. In September, there was the minor increases in FT4 and FT3 described in the paragraph above after an increase in dosage, but my TSH was 0.02. I should get the results of my most recent blood tests tomorrow to take to the appointment.
The first paper listed won't be any use in a TSH argument when TSH is below 0.04, but is very useful when 0.04 / 0.05 or above .
However the 2nd paper listed on there can be useful even if TSH is lower than 0.04 ~ (the one about long term bone density / 'subclinical hyperthyroidism' ( deliberately supressed TSH / fT4 in rage on levo) as part of treatment following thyroid cancer
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At the end of the day it's about balancing statistical / theoretical risks of future bone /heart problems vs. the very definite current risk to heart / bones from feeling so unwell that you don't get enough physical weight bearing exercise to keep bones and heart in good condition anyway .
There's absolutely no point him raising your TSH to a level that removes all theoretical risks, if doing so sticks you on the sofa feeling yuck for most of the next 30 yrs ... because that will definitely give you real heart problems and real bone loss.
I have told my GP that i understand and accept the 'risks' (as he sees them) of Atrial Fibrilation which increases risk of stroke , and increased bone loss.... but that i choose 'quality of life' as the more important factor for me. My Tsh was 0.05 ish for many yrs on levo,, so i've had to have a few 'discussions' with GP about it.
He's now written a note to this effect on my notes to cover his back (in case i drop dead) . which is fair enough.. GP's/endo's risk getting into trouble themselves with the GMC if they just let us have low / supressed TSH without trying to persuade us to increase it ,as the current guidelines say it's a risk.
Thank you again, so very much. The phrase that really leaps out is the idea of them trying to persuade us to increase our TSH. I totally understand their point of view. You're right, I've been on a two-year journey of failed persuasion, as my key figures (FT4/FT3) plummet and my TSH only changes very slightly. You also capture it perfectly about sitting on a sofa for the next 30 years and the risks this would give rise to. I've been doing physio for the past year for a knee problem but am making very slow progress as I feel too weak and tired a lot of the time. I walk for exercise as it's about all I can do when I would rather be active. I call it low bandwidth, I just don't have the capacity to do very much without getting very tired, and after doing my physio exercises feel like I have a cold coming on as it wears me out. I must admit I hadn't really thought of it that way. I'll check out those links too, thank you again.
Absolutely! In a funny little quirk, I've realised that the exact text sent to me by the endo about grain equivalence is lifted directly from.... the Thyroid UK website! Wonder if he hangs out here?!😀
I am the same but I don't know why. On Thyroid s NDT for seven years and feeling well.
They changed the formula and now I am trying to sort out Levo/T3 without much luck. It's been over 6 months now and I still feel really ill.
The fast release of the T3 doesn't suit me and my levels are all over the place. The T3 in NDT is released slowly. After starting on NDT back in 2015 it only took about 10 days for me to start feeling well again.
You are absolutely spot on. I've just had a quick read of the diogenes post that Tattybogle has linked in the comment above and can see that it's a slower release issue and uptake issue (if I've understood it correctly) that makes NDT more effective. I've just had my blood tests done by a nurse who is also on NDT and we were both speculating that while we're not conspiracy theorists, there is definitely something odd going on in the background that prevents 'the establishment' making NDT available. Looking at diogenes' comment, he's probably right - you can't patent a pig!
My father was a pig farmer and pigs have a mind of their own, for sure. When I found out as a very young child that we ate the pigs I was so upset that I never ate pork in my life, then of course I had my thyroid removed and went down the NDT pig route. Ironic.
That's certainly my next port of call and a lovely person from the forum has already recommend one to me, plus the nurse doing my blood test this morning is also on NDT and has recommended someone, who is on the Thyroid UK list. I think it's just the cost of everything....
I was on Armour in the early days of self-medicating, but it cost an arm and a leg plus became more difficult to source. I'm noting your bits and pieces you say you have around in your other message and will be looking them all up!
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Angela
Switch from t3 & t4 combo to NDT
People on NDT and Levo combo - has this raised your ft4 and made you feel better?
Help please. Reacted to levo and seem same on ndt. Will t3 be better for me?
NDT & Thyroxine 
