Becoming resistant to NDT dosage?: I posted this... - Thyroid UK

Thyroid UK

139,194 members163,361 posts

Becoming resistant to NDT dosage?

CrimsonMacaw profile image
18 Replies

I posted this question initially over on the Ray peat forum, but I'm cross posting it here to see if I can get a different measure of advice and a better perspective:

For the past few months I've been taking NDT and T3 (Tertroxin here in Australia) and getting my FT4, FT3 and TSH checked every 4-5 weeks. I've had autoimmune hashimoto's (antibodies have dropped quite significantly over these last 1.5 years from around 200 to around 50) for the past several years but have only needed to start taking meds around 2 years ago. And after a year or two of haphazard experimentation with T4, NDT, and T3, it was only several months ago that I finally realised that I need both T3 and T4, or T3 and NDT since I'm unable to produce either T3 or T4 in sufficient quantities, and when I take NDT by itself then I just get a buildup of T4, without a similar buildup of T3.

Initially I started off on 100mcg of T3 per day, but over time I've had to up that to around 140-160mcg to get my T3 levels within the upper part of the normal range.

Anyway, the main issue for me isn't the FT3, but the FT4. I've been taking the Ancestral Supplements NDT thyroid at a dose of around 8 capsules/day for the past several months. Each capsule contains 30mg beef thyroid and 470mg beef liver. Initially during the first 2 months, at the 8/day rate I was able to get my FT4 in the upper half of the normal range, which meant that along with the healthy levels of FT3 I was actually feeling quite well. However, over time (specifically these last few weeks), my FT4 levels have been dropping, despite maintaining the same dosage. Right now they're at the very bottom of the normal range and it's causing all my old hypothyroid symptoms to return (cracking skin, constipation, lethargy and fatigue, lack of mental clarity, etc.)

Now my question is, is it possible to become acclimated or resistant to a certain T4/NDT thyroid dosage over time, which would require me to constantly continue increasing it ad infinitum, or is there something else at play? I know a lot of people who start off on thyroid meds, be that T4, T3 or NDT initially feel great and then after several weeks or months, the old symptoms set in and they need to increase their dosage - but in many instances that doesn't work since an increased dosage provides symptom-relief for another few weeks and then it stops working again.

In my case, I've narrowed it down to the FT4, so I know it's not the T3 medication that I'm becoming used to. If it is a case of becoming resistant to NDT/T4, would the best course of action be to stop taking NDT for a certain period of time so that sensitivity to it is restored, or just increase the dose again?

Would there be any underlying issues (e.g. chronic infections, etc.) that could cause the body to severely downregulate FT4 levels whilst consistent levels of T4 medications are still being taken?

I'm based in Australia, and my results are as follows (I'm not posting TSH because as soon as I started on NDT several months ago, it became suppressed, and I think that T3 by itself also suppresses it):

July 2019 (140mcg T3, 8 capsules NDT ~ 240mg thyroid)

Free T4: 11.4 (9.0 - 19.0)

Free T3: 6.2 (2.6 - 6.0)

June 2019 (140mcg T3, 6 capsules NDT ~ 180mg thyroid)

Free T4: 14.7 (9.0 - 19.0)

Free T3: 4.3 (2.6 - 6.0)

May 2019 ( 140mcg T3, 8 capsules NDT ~ 240mg thyroid)

Free T4: 19.2 (9.0 - 19.0)

Free T3: 6.0 (2.6 - 6.0)

April 2019 (100mcg T3, not taking NDT - had hypothyroid symptoms)

Free T4: 10.0 (9.0 - 19.0)

Free T3: 3.2 (2.6 - 6.0)

My antibodies were last checked in March 2019 and were:

Anti-TG: 27.3 ( <4.1)

Anti-TPO: 40.2 (<5.6)

In December 2017 they were around the 200 mark and the hypo symptoms were still the same without the medication.

Written by
CrimsonMacaw profile image
CrimsonMacaw
To view profiles and participate in discussions please or .
Read more about...
18 Replies
Timsywhimsy profile image
Timsywhimsy

I don’t know if this is a good answer or not but I remember when I first started t3 ( just 5 mcg) initially—first two weeks—t4 stayed the same and t3 rose. As expected. But when we checked again at 6 weeks t3 was the same but t4 went down. Apparently it’s a thing—I’ve even seen it mentioned in studies. I don’t know what it is. If it’s your bodies way of saying it has enough t3 so it’s not bothering with the t4????

Blueskyyy profile image
Blueskyyy in reply to Timsywhimsy

That’s why doctors prescribe combo T4+ T3.

A combi T3+T4 can help you keeping both FT4 and FT3 in the upper half of range.

It you take only T3, you will reduce your own T4 production

TSH110 profile image
TSH110

I think on NDT it is free T3 that is the important value (in top 1/3 of range - yours is right at the top or going over range) and FT4 goes quite low. Others with more knowledge will probably reply.

greygoose profile image
greygoose

FT4 levels will always drop when you start taking T3.

But, I'm not quite sure what it is that you're taking. Beef thyroid and beef liver doesn't sound like any NDT I know. Sounds more like a glandular, which may of may not contain any hormone. NDT is specific in that it contains 38 mcg T4 and 9 mcg T3 per grain. Does your beef 'NDT' specify how much hormone it contains?

Also, your FT3 is pretty low for someone taking 140 mcg. So, how do you take your T3? Do you take it on an empty stomach and leave at least one hour before eating or drinking anything other than water? Do you take any other medications/supplements at the same time as your T3? You don't seem to be absorbing it very well.

As for the antibodies, the fact that they've dropped means nothing. They fluctuate. But, if you've had them over-range just once, you have Hashi's, and Hashi's doesn't go away. So, personally, I wouldn't even bother retesting them. They don't do anything much, anyway. :)

CrimsonMacaw profile image
CrimsonMacaw

Also something that I noticed over these past few months of trying different NDT brands alongside T3, is that the Ancestral Supplements Thyroid with Liver was the one that had the best effect at making me feel normal (at least up until a few weeks ago). I've switched over to Thyro-Gold NDT around a week ago and have been taking two 300mg capsules every morning and my hypothyroid symptoms have slowly been getting worse. I'll check my thyroid levels, alongside my antibody levels, in another month to see where everything stands, but it could be that although the Ancestral Supplements NDT was providing less thyroid, the additional beef liver may have been providing some other nutrients I was sorely lacking. Or maybe it's just that the Thyro-Gold NDT isn't on the same level as other brands. In Australia it's not possible to get WP Thyroid, and the only other option is to go with Armour.

However, as mentioned by some on the Ray Peat forum, taking such a large dose of beef liver could quickly lead to vitamin a toxicity - I'm not sure if that's indeed the case, but it something to consider.

The only possibility other than an increase in antibodies (which I'll check for later) is the pooling issue that is mentioned on the Stop the Thyroid Madness site.

EDIT: greygoose I just saw your response as soon as I posted this message.

The Ancestral Supplements brand says it has 30mg bovine thyroid and 470mg bovine liver from grass-fed NZ cows per capsule. The Thyro-Gold NDT says its has 300mg bovine thyroid per capsule - also from grass-fed cows. I'm not sure if the two are extracts (a la Armour) or just the entire glandular. And no, neither of the two brands specify how much hormone they contain because they're sold as supplements and therefore there's different rules dictating how they're allowed to describe their contents or whatever.

I take my T3 and NDT all at once in the morning around 40 minutes before a very light breakfast - not with any other medication. Usually within 5 - 10 minutes I'll feel a warmth going throughout my body which lasts maybe for half an hour. Also, I should mention that 1 - 2 months ago, I was getting very slight hyper symptoms from the dose I was taking (however it was also relieving the chronic slow digestion/constipation issues I've had since I became hypo), but over the past month I've felt absolutely no hyper symptoms, and actually I've been getting hypo symptoms more often than not.

greygoose profile image
greygoose in reply to CrimsonMacaw

Thyro Gold is another thing entirely. They don't advertise the amount of hormone in it because then it would become prescription only. But we do know the hormone content, and it is more or less equivalent to other NDTs. Whereas your thyroid/liver tablets are just a glandular.

But, as you said, liver contains a lot of nutrients - including iron - so if you combine liver with thyroid, any hormone in the thyroid would bind with the iron and become unavailable. So, what you have been taking won't be giving you any thyroid hormone, no. It will have improved your iron. But it also contains a lot of vit A, and too much vit A is toxic.

It might be better to leave a full hour before your breakfast, so that the hormone has time to leave the stomach.

So, all in all, not surprising that your FT4 has dropped, is it? :)

in reply to CrimsonMacaw

Just out of curiosity: do you know why the manufacturer included liver in this product? Liver contains iron, and it's normally recommended to take iron supplements several hours away from thyroid meds in order not to decrease absorption of thyroid hormone. There are several supplements called "glandulars" (with no or some unspecified amount of thyroid hormone depending on the product), but I've never heard of any containing iron and cannot see what possible benefit it could have in this context.

in reply to

OK, so I looked this product up, and the manufacturer clearly states on his website that: "Grassfed Beef Thyroid is a natural, whole food dietary supplement, unlike Armour, Naturethroid, Westhroid-P (WP) and NP Thyroid which are concentrated USP thyroid extracts derived from porcine."

It goes on to say that eating healthy organs from animals can strengthen and support your own weak organs, meaning this product would support both your thyroid and your liver.

TBH, I am not sure this product will have much long-term effect if you have primary hypothyroidism.

In fact, you are getting unregulated and unknown amounts of thyroid hormone every day, which means your hormone levels must be fluctuating wildly all the time.

Have you considered prescription NDT or a synthetic T3 + T4 combo?

CrimsonMacaw profile image
CrimsonMacaw in reply to

I still need synthetic T3, because NDT just by itself only raises my FT4. As mentioned in the previous reply, the other NDT I have tried is Thyro Gold, but I'm not getting a good response from that. In Australia, the only NDT that's available from local pharmacies is Armour, so that is the other one I could try alongside T3.

in reply to CrimsonMacaw

I see.

Armour works for some and not so well for others since it was reformulated ten years ago. It seems the added cellulose creates problems for some users.

Are you sure you need NDT, or could you try synthetic T3+T4 instead? The advantage would be that you could tweak dosages more easily as prescription NDT contains a fixed ratio of the two hormones.

Prescription NDT is 80% T4 so each increase means you'll be getting primarily T4, and only a little T3.

There seems to be general consensus that the fact that many feel better on NDT than on T4 only is because they needed the additional T3. However, I have not seen any convincing evidence that the other substances in NDT - T1, T2, and calcitonin - make a difference when it comes to the treatment of hypothyroidism. In other words, it's the T3 in NDT that makes people feel better because they were T3 deficient on T4 only. So, although on NDT myself, I don't believe that everyone needs or even should be on NDT just because they need T3.

I did not mean to imply that you are wrong to take the Ancestral supplement, only that I doubt it's intended to treat primary hypothyroidism (where the gland itself is dysfunctional). The manufacturer states it's intended to support and nurture weak organs, but that does not make it a prescription strength drug and may not replace the hormones your own thyroid gland is incapable of producing. To me, it's like adrenal glandulars intended to strengthen the adrenal glands in people with adrenal fatigue where the adrenal glands themselves are not damaged, just overworked. They would not be enough in someone with adrenal insufficiency (dysfunctional glands), which is why I wonder if the supplement you're taking is enough for someone with a dysfunctional thyroid gland.

What is your diagnosis (Hashimoto's, Graves', etc)?

CrimsonMacaw profile image
CrimsonMacaw

I may have been unclear in the original post, but that 8 capsules a day of Ancestral Supplements NDT (which comes out to 240mg of beef thyroid and around 3.5g of beef liver) got my FT4 from 10.0 (range is 9.0 - 19.0) in April when I was feeling awful with many of the classic hypo symptoms, up to 14.7 in June when I was feeling much better, but still not 100% with my bowel movements still slightly sluggish but much better than before, and then it dropped to 11.4 in July on that same dose. I decreased the dose slightly in May, but then returned to where it previously was later on in May/June.

I'm wondering if this could be associated with thyroid pooling or just this particular supplement? Or as mentioned previously, could I just be becoming accustomed to this dose and need a larger dose? However, as I've mentioned 2 capsules of the Thyro Gold (which I assume is the equivalent of 2-3 grains of Armour NDT) every morning for over a week haven't improved my symptoms.

Angel_of_the_North profile image
Angel_of_the_North in reply to CrimsonMacaw

I don't think that thyroid pooling exists - there is no evidence that it does. If you have Hashis your results will vary anyway, and it is your free T3 that is most important, although your production of free t4 and conversion will improve when iron , B12 and folate are good - taking liver will have helped with that. Why don't you just take a "proper" NDT or T4/T3 combo (or in Australia there is Thyrovanz which is similar to ThyroGold) - it would probably be cheaper as well as more effective? Your T4 will drop when you have enough T3 (unless your thyroid has been removed) so that's what your recent results are telling you. I suspect that most of your improvements are from taking t3, not glandulars, and improving your iron/b12 status. But you'd do better to split your T3 into 2 or 3 doses a day at least an hour away from meals.

Timsywhimsy profile image
Timsywhimsy in reply to Angel_of_the_North

Out of curiosity, does t4 only drop when you’ve got enough t3? Is that a good way to dose? I feel like my t4 drops if I take my t3 all at once but not if I split it three times a day. Anyone else experience this?

CrimsonMacaw profile image
CrimsonMacaw in reply to Timsywhimsy

That could actually be a possibility, as I initially used to split my 140mcg T3 dose - 100mcg in the morning alongside NDT, and 40mcg in the mid-afternoon. However, over the past month I've been taking that dose all at once. I'll try going back to taking a split T3 dose as I was before and see if that prevents it from suppressing my FT4 (or not allowing the NDT to work as well as it should).

Angel_of_the_North As I mentioned, when I was taking T3 by itself, it did not make me feel much better, it simply raised my FT3 levels back into range. It was when I added in the Ancestral Supplements NDT that my FT4 moved up and I started to feel much better. However, when I tried taking NDT in the past without T3, my FT4 was high in the range, but my FT3 was low and my hypo symptoms were all still there.

I do agree that the beef liver was providing me with some minerals/vitamins that I was lacking, however, for one reason or another those vitamins and minerals weren't as essential as I thought they were because my FT4 still dropped and the hypo symptoms returned. So as I said, I'll stick with this Thyro Gold NDT for a while, but I have read countless threads on this forum where people are noting that the NDT dosage that was helping them for months no longer works and they need to keep increasing it. I'm wondering if they ever reach a point after many months where they no longer need to increase and they stabilize?

Angel_of_the_North profile image
Angel_of_the_North in reply to Timsywhimsy

My T4 drops whether I take T3 all at once or split the dose. But i find that I feel better on a split dose. I don't know whether anyone has actually researched why t4 drops when you take T3.

RockyPath profile image
RockyPath

To answer your original question, I've seen a study where lab mice were exposed to exogenous T3 for a period of time. A group of control mice had no exposure. All mice sacrificed their lives at the end of the experiment to have their tissues studied for the presence of T3 receptors on cells. Over time, the body develops additional T3 receptors in response to exposure. At least in mice. Nearly all animals rely on thyroid hormone for energy production, so you'd think this applies to us as well.

When I reported this to my endocrinologist, he only expressed exasperation. "THIS IS NOT IN ACCORD WITH ACCEPTED CLINICAL PRACTICE."

Good luck.

Ness54 profile image
Ness54

I wish somewhere that was written down and official so I could print it off and show him to stop him giving incorrect advice to his patients, if you know where it is officially written please let me know. Thanks

CrimsonMacaw profile image
CrimsonMacaw

I know that most mice study results don't pass over to human studies, but if there is an increase in T3 receptors, would it stand to reason that there would also be an increase in T4 receptors if T4/NDT was supplemented, requiring an increased dosage of T4/NDT to fill those receptors? That could be the reason why many seem to need to take more and more over time.

Also, would splitting an NDT dosage into 2-3 times per day be better than taking it all at once, and does anyone know the mechanics of why an NDT or a T3 dosage taken all at once has a different effect than that same dosage spread throughout the day? If a large single T3 dose at once prevents the FT4 from rising, then maybe a large single NDT dose would similarly prevent the FT3 from rising.

You may also like...

NDT results, advice appreciated as always.

8 (9.0-19.0) Free T3 - 4.2 (2.6-6.0) TSH - 0.13 (.03-4.0) I took my Capsule 120mg, after my...

Bovine NDT dosage advice

NDT dosage advice- would 40mg NDT be equivalent to 40mg synthetic thyroxin? Starting Allergy...

NDT : TEST RESULTS : OVER MEDICATING : WHAT DOSAGE?

grains over 7 months and have been on that dose since - the only real symptom changes I've noticed...

Ndt and insulin resistance

june 3_25 range. I was on 1 grain ndt. Then i dit go up to 105 mcg ndt. Almost 2 grain. I am on a...

Dosage and Timing Of NDT

best way to attain the right dosage and timing? Sometimes I can feel NDT wearing off. For instance...