Is NDT (Natural Desiccated Thyroid) the Best Thyroid Medication?
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Is NDT (Natural Desiccated Thyroid) the Best Thyroid Medication?

Natural desiccated thyroid is a thyroid medication that comes from pigs!

This medication contains a more "complete" profile of thyroid hormones when compared to almost all synthetic thyroid medications out there. 

This has lead many people to tout NDT as the "best" thyroid medication. 

In this article, we are going to explore this claim while also discussing the pros and cons of this medication. 

You'll learn who should use this medication, who should avoid it and the pitfalls of using it

Let's dive in: 

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What is NDT or Natural Desiccated Thyroid Hormone?

NDT or natural desiccated thyroid hormone is simply a type of thyroid hormone medication. 

It can be used to treat people who have low levels of thyroid hormone in their body from conditions like Hypothyroidism and Hashimoto's thyroiditis. 

NDT is often claimed to be one of the "best" thyroid medications out there because it's considered to be all natural. 

So, with this in mind, let's break apart what NDT actually is. 

First:

Where does NDT come from?

NDT is porcine-derived which means that it comes from pigs. (1) 

To get NDT, people must take the thyroid gland of pigs and desiccate or dry it out. 

From there it is standardized to a specific dose and contains 38mcg of T4 (the inactive thyroid hormone) and 9mcg of T3 (the active thyroid hormone) in each grain. 

Grain is just a way to standardize the dose of NDT between different brands. 

Natural desiccated thyroid also contains other hormones and prohormones such as other types of thyroid hormone (T1 and T2).

These hormones are not nearly as active as T4 and T3 but they are thought to play an important physiologic role in the body otherwise, (2) why would your body produce them?

Each grain of NDT contains around 76% T4 and around 23% T3 which is a ratio close to the 80% T4 and 20% T3 that your thyroid produces naturally when it is healthy. 

T3 conversion booster results

For this reason, and because it contains prohormones, and because it comes from a natural source, (3) many people believe it is one of the most complete thyroid medications out there! 

While this may be true, it doesn't mean that it works equally well for every single person. 

Let's dig into the basics of NDT and talk about why it may not be the best medication. 

Natural vs Synthetic Hormones

NDT is considered to be natural because it is sourced from a "natural" source, pigs. 

This sourcing of thyroid hormone is different from the approach used to create other formulations of medications such as Levothyroxine and Synthroid

Other medications are created in a laboratory from other basic compounds. (4) 

But you must always remember that ALL types of thyroid medications are considered to be bio-identical which is very important. 

Bio-identical means that the hormones you are taking by mouth are considered to be IDENTICAL to the hormones that your body produces naturally!

Where these medications differ is in the SOURCE. 

The source for NDT is from pigs while the source for Levo and Synthroid is other chemical structures. 

Some people believe that naturally sourcing thyroid hormone is superior to creating it chemically in a lab. 

From my perspective, there is no difference between thyroid hormone from a human or pig when compared to thyroid hormone created in a lab

Both compounds look the exact same and function in a similar way in the body. 

Where they differ is in the other hormones and pro-hormones that come in NDT formulations. 

NDT Brands

Let's take a second to discuss the various brands of natural desiccated thyroid hormone out there. 

There are several "well-known" brands and some less well-known brands. 

What you need to understand is that these medications do differ in the type of active and inactive ingredients in them but they all contain both T4 and T3 thyroid hormones. 

While it may not sound like the inactive ingredients make a big difference, they actually may be the reason that some people simply can't tolerate certain types of NDT brands. 

For instance:

It's not uncommon for someone to be on Armour thyroid but not feel well when switching to Nature-throid or WP thyroid even if their dose stays the same. 

These differences are likely the result of how your body interacts with the inactive ingredients and how difficult it is for your intestines to break down and absorb the hormones in the medication. 

What that means for you is that if you don't tolerate one type of NDT brand it doesn't mean you won't tolerate all of them. 

Instead, you may want to switch to a couple of different brands to see if you can find one that works for you. 

With that in mind you can find a list of NDT brands below: 

Is NDT Superior to T4 Medication for Hypothyroidism?

It is largely felt by many online communities that natural desiccated thyroid is the single "best" thyroid medication out there. 

This logic has lead people to believe that if you are taking NDT and it isn't working for you that the problem must be with your dose and not with the medication itself. 

I'm not a fan of this approach and don't believe that when it comes to your thyroid that there is a single "best" thyroid medication. 

A better approach is to always listen to your body while you look at other problems beyond your thyroid

Thyroid tunnel vision can lead you to believe that every problem you have is associated with your thyroid and that adjusting your dose is the solution to this problem. 

This approach to management has lead many patients to take higher than necessary doses of thyroid medication and can be dangerous! 

So, while NDT is a great medication, it's certainly not the "best" or the only thyroid medication available. 

The type of thyroid medication that you use, and your dose, should be individualized to YOUR body. 

Natural Desiccated Thyroid for Weight Loss

One important note worth mentioning is that of weight loss and NDT. 

Some studies, like this one, have shown that switching to NDT does result in modest weight loss in certain patients. (5) 

This particular study took a look at 70 patients that were already taking T4 medication (Levothyroxine). 

This group of patients was taking this medication and despite having a normal TSH still had some symptoms of hypothyroidism. 

Thyroid lab tests in patients taking natural desiccated thyroid compared to T4

These patients were then randomized and given NDT (desiccated thyroid extract) for 16 weeks and then placed back on their old medication. 

During the period that these patients were taking NDT, they noticed around a 3 pound weight loss on average and roughly 50% of patients taking NDT wanted to stay on it. 

Not only did they lose weight but they also reported feeling much better on the medication in a subjective sense (based on their own opinion). 

3-4 pounds may not sound like a big deal to you, but when you realize that weight is incredibly difficult to lose when you have hypothyroidism this is actually a great feat. 

But does this mean that the weight loss is due to NDT itself or simply due to the T3 in the medication?

While we don't have definitive studies, it's logical to believe that the same results would have been achieved by simply adding T3 (in the form of Cytomel or Liothyronine) to existing doses of T4 in these patients. 

So, while NDT can certainly help you lose weight if you have hypothyroidism, don't fall into the trap believing that the weight loss is caused by the NDT itself. 

Instead, the weight loss is most likely the result of IMPROVING the total T3 and free T3 levels in your body! 

And this can be done with T3 medication of any type. (6) 

Common Problems and Symptoms when using NDT

Let's talk about some of the problems associated with NDT use. 

The way that your body responds to NDT is going to be different from other people out there. 

This means that the type of NDT that you use, and the dose that you use, all may potentially lead to problems. 

What's important is to focus on how YOU feel and how YOU tolerate the medication. 

By listening to your body, and by checking your thyroid lab tests, you can be certain that you are taking the right dose for your body. 

You can find a list of the most common problems that patients experience when they use NDT below: 

  • Some people take too much natural desiccated thyroid hormone - (7) Overdosing on NDT is a common problem because many people believe that higher doses will somehow improve their thyroid function. This leads to overdosing and symptoms of hyperthyroidism in some patients. This problem stems from "thyroid tunnel vision".
  • Dosing is static which means you can’t tweak the T4 and T3 concentrations - NDT comes in a static dose of 38mcg:9mcg of T3. This means that you can't individually adjust the amount of T3 in the medication without also adjusting the T4. You might do great on 38mcg of T4 but may need something like 5mcg of T3. If you fall into this category then you can't adjust your medication. 
  • May lead to variations in free T3 & Free T4 levels - Some people experience very high free T3 levels and very low free T4 levels even when using low doses of NDT. This problem probably has to do with how each individual processes thyroid hormone in their body. 
  • Symptoms arise from the use of T3 which can be difficult to manage in some patients - (8) Some patients are exquisitely sensitive to even incredibly low doses of T3. These are patients that would probably do fine on certain types of T4 medication (such as Tirosint) but do poorly when they start even low doses of NDT. 
  • May be hard to break down for some patients in the intestines - This problem isn't unique to NDT medications, but it's worth considering if you have intestinal issues. Inactive dyes and fillers may cause reactions and may make digestion of NDT difficult. 
  • May lead to immunogenic reaction (may not be ideal for patients with Hashimoto’s) (9) - There is a theoretical risk that taking a foreign pig-derived substance can "flare" up the immune system and worsen thyroid function in patients with Hashimoto's thyroiditis. I don't think this is a reason to completely avoid NDT if you have Hashimoto's thyroiditis but you should be aware that it can happen.

Overdosing on NDT

Believe it or not but doctors have been using NDT since the 1950's!

Even back then it wasn't uncommon for doctors to prescribe high doses of NDT (up to 3 to 8 grains per day) to patients. (10)

This was way before thyroid lab tests were created, so dosing was often based on the "Basal metabolic rate" which is a marker for metabolism. 

These doctors found that increasing the dose of NDT did result in modest weight loss by increasing the metabolism, but once the dose was lowered, the metabolism of the patient went back down to below normal levels. 

This is as relevant today as it was back then. 

Currently, many people believe that by simply increasing their dose of NDT that they will finally feel better and relieve their symptoms. 

This happens frequently in patients who are suffering from weight gain. 

This leads to higher and higher doses of NDT which dramatically suppresses the TSH and temporarily helps with weight loss. 

But the unintended effect is that it may also cause long-term harm because of the high dose of NDT being used. 

Studies dating back to the 1950's showed that if you are responsive to NDT you only need a small dose (usually 1-2 grains) to improve your symptoms and improve your metabolism. (11) 

If you are still feeling symptomatic at that point then some of your symptoms are likely related to some other problem or some other hormone imbalance!

You can avoid these potentially negative side effects by using only the appropriate dose and by monitoring your thyroid lab tests in the process. 

Who should use NDT

NDT is a great medication and many people out there stand to benefit from its use. 

I've compiled a list of just some of the patients that tend to do the "best" on this medication below: 

  • Those who have failed T4 medication - If you've been on T4 medication such as Levothyroxine or Synthroid and you just aren't feeling well after 6-8 weeks then it may be time to consider a T4/T3 combo medication. 
  • Those with low free T3 levels (usually need a T3 medication) - Up to 15% of the population suffers from thyroid conversion issues which means they don't convert T4 into T3 as well as other people. If you fall into this category you may have a "normal TSH" but your free T3 and total T3 levels may be lower than normal. If you fall into this category then adding T3 (from either NDT or Liothyronine) may help bring these levels up and help you feel better. 
  • Those who are post-thyroidectomy - Your thyroid (when functioning normally) produces around 80% T4 and around 20% T3. If you don't have a thyroid, because it was removed or destroyed, then it makes sense to supplement with thyroid hormones close to this ratio. Most post-thyroidectomy patients take only T4 medications (so 100% T4) which do not contain T3. Some of these patients don't feel well despite having a normal TSH. Taking NDT can provide your body with T3 in a ratio which is close to what your body produces naturally and may help those without a thyroid. (12)

This is not an all-inclusive list but it can help get you started! 

Conclusion

Natural desiccated thyroid is a thyroid medication which contains both T4 and T3. 

Because of this, it may be one of the better thyroid medications (but not the best!) out there. 

If you have thyroid issues and are struggling with low free T3 levels, with weight gain and/or other symptoms despite having a normal TSH, then this medication may help you

When using it be careful to watch for side effects such as anxiety, heart palpitations or hot flashes which may indicate that your dose is too high. 

Now I want to hear from you:

Are you taking NDT? Is it working for you?

Are you not tolerating NDT?

Is it causing negative symptoms?

If so, leave your comments or questions below!

I'll do my best to respond to each comment. 

Westin Childs
 

Dr. Westin Childs is a Doctor of Osteopathic Medicine. He provides well-researched actionable information about hormone-related disorders and formulates supplements to treat these disorders. He is trained in Internal Medicine, Functional Medicine and Integrative Medicine. His focus is on managing thyroid disorders, weight loss resistance, and other sex hormone imbalances. You can read more about his own personal journey here.

Click Here to Leave a Comment Below 21 comments
Laurie - July 7, 2018

Hi- been taking Armour 120 mg for a couple of years. It was very helpful compared to Levo. However low thyroid symptoms have been back for over a year.
Currently, TSH has been .008 to now .012
T4 has been .80 now 1.15
T3 5.3 to now 4.2
Endo just lowered to 90 mg. Been having symptoms of hypothyroid the whole time. Do you have any suggestions to help alleviate the symptoms? or doing/weaning schedules? Really would appreciate your input and direction. Thank you!

Reply
    Westin Childs - July 7, 2018

    Hi Laurie,

    I’m not sure that weaning down further would help your symptoms any. Instead, you may want to focus on strategies to help what thyroid hormone you have in your body function. You can do this through diet and supplements to start with and ultimately you may need to adjust your medication further.

    Reply
Anne - July 7, 2018

Hi,
Appreciate the informative article. I take 2 1/2 grains of NDT and feel good for the most part and my labs look great. My thyroid antibodies have gone down to 9 from several hundred as well. My main complaint still though, is lack of weightloss -despite not eating gluten, dairy, soy, artificial sugars, etc. faithfully for 5 years . I could stand to lose about 40lbs so it’s just so strange! Any thoughts??

Reply
    Westin Childs - July 7, 2018

    Hi Anne,

    I probably have 5-10 articles on why weight loss is difficult in thyroid patients on my site that should help quite a bit! I would start here and then go through the others: https://www.restartmed.com/lose-weight-hypothyroidism/

    Reply
      Anne - July 8, 2018

      Ok, thank you!

      Reply
Genia Moody - July 7, 2018

Earlier this year, I wasn’t converting my T4 to T3 and I was anemic. My anemia was corrected with an iron supplement and a good quality probiotic (after reading your studies). Thanks to you I avoided wasting time and money at a gastroenterologist. Just wondering why my endocrinologist never even considered giving me T3…that seems like a simpler solution. I’m 15-20 pounds heavier and struggling to lose the weight. My thyroid and synthroid are always causing my weight to swing. I can be a size 4 or size 12 in a matter of months. Ready to get off the roller coaster! I need you as my doctor! You get it!

Reply
    Westin Childs - July 8, 2018

    Hi Genia,

    Most physicians won’t prescribe T3 usually because they aren’t familiar with how to dose it or what to do with some of the symptoms that may arise.

    Reply
Chelsea - July 17, 2018

Hey Dr. Westin,
So I was diagnosed with hypothyroidism in February of this year after mainly having more hyperthyroid symptoms. I feel like I have lost part of who I am. I use to be able to do triathlons and feel like I could get so many things done in the day along with taking care of my two kids who are 3 and under. But after finding out I had hypo they put me on levo, and then kept increasing my dose all the time. I didn’t feel any better and my heart seemed so erratic along with feeling out of breath. So I asked my primary to switch me to Nature throid which he did at 1grain since the middle of April. Which seemed to help my mood, brain fog, and shakiness that I had experienced on Levo. I have been losing weight this whole time. I’m 5’3″ 116lbs which is what I weighed in high school and I’m 30. I still feel like I have so many issues. I did get my ferritin/iron checked and was not anemic but not optimal so I’m going to go in soon to see if the supplementation of iron is helping though I still feel fatigued and weak most days, especially after having my period. I’ve tried so many supplements and diet changes and feel neurotic and helpless.
my symptoms now
jittery
trouble sleeping
constipation
aware of my left descending colon not painful just discomfort
unintentional weight loss 123lbs in Feb 116lbs now
anxiousness
obsessed with my health
weakness/fatigue
unable to handle exercise
mood changes
aware of my heart beat at different times of the day

Any suggestions, or labs? wondering if I also might have blood sugar issues even though my A1C was normal. Ugh Sorry to throw all of this on you. But I’m guessing you might be used to this.
Thank you for any suggestions.
-Chelsea

Reply
    Westin Childs - July 17, 2018

    Hi Chelsea,

    The first thing you should do is get a full hormone panel which includes both sex hormones and your thyroid. This information will really help you to determine where these symptoms are coming from but without this information you really won’t know where to start.

    Reply
Roche - July 21, 2018

Hi Dr.Westin Childs, just asking something quite confusing. Just got a bottle of Armour thyroid. The label stated 1/4 grain is (15 mg) and then under, stated that each tablet contains:

levothyroxine (T4)…9.5 mcg
liothyronine(T3)…..2.25mcg

And on the table guideline, 1/4 grain (15mg) contains levothyroxine T4-9.5 mcg and liothyronine T4 -2.25 mcg
The question: what is right? Just about switching from synthetic Levo to Armour … Hoping for your reply…thank you.

Reply
    Westin Childs - July 21, 2018

    Hi Roche,

    I’m not sure I understand your question, it looks like the numbers checkout to me based on the 1/4 tablet you mentioned.

    Reply
Paige L Danielson - July 30, 2018

Morning,
I have watched all of your videos more than once and have read all of your posts. My question is this:
I was switched to Armour 90mg, from Synthroid 100 (but just before that the Synthroid was lowered to 88 as I was having hot flashes).
Free T3 5.80
Free T4 1.0
Super cold hands and feet still. Morning temperature is 97.7

I was on 60mg Armour with results of
Free T3 4.1
Free T4 0.8

However, when I was on Synthroid only my Free T3 was extremely low and I felt achy all the time.

I don’t know my Reverse T3 number. But my Ferritin is 215.
I am lost as where to go next. Thanks.

Reply
Shelly Harris - July 31, 2018

Hello Dr. Childs!
Thank you for all your wealth of knowledge and all your great & helpful articles.

I just got back my latest thyroid function results.
TSH: 0.10 (past .32 & .21)
T3: .900 (past .620 & 1.310)
T4: [email protected] (past 4.43 & 4.89)
T3,free: 2.87 (past 2.40 & 4.14)
FT4.N: [email protected] (past 0.91 & 0.86)
Anti-TPP AB: 1 (past 1 & 0)

I was on NT 2 32.5 mg then bumped to 3 32.5 then after these results bumped back to 2. I started NT Aug 2017. The second number in past results is from that date and the 1st past number is from March 2018) then my current reading. I’m 56 and have been on this long health journey. I’m one to be wired at night and sleep till 1 pm daily :/
I’ve also had an ongoing infection on my chin for past 2 years that won’t clear.., Staph folliculitis. I’m gluten dairy and mostly sugar-free as well. I’m thin as well.

I’d love your opinion and suggestions would be greatly appreciated! Thank you so much.

(More info: My NP said the medication is not working and there’s no alternative. She suggested going back to 2. I also came up with strong allergy to pork yet I don’t eat pork. Could it be from the NT? I’m below low in all my blood levels too. )

Reply
    Westin Childs - July 31, 2018

    Hi Shelly,

    Your best bet is to seek out a knowledgeable physician to help guide you as you will probably need more advanced hormone testing to figure out what you need. You can find more information on how to do that here: https://www.restartmed.com/thyroid-doctor/

    Reply
Kris - September 3, 2018

Hi Dr Child’s,
Thank you so much for taking questions. I have listened to all of your videos and learned a lot. I was on 125-150mg synthroid for 20 years and never felt right. I started Erfa NDT 3 months ago and am currently on 2.5 grains(150 mg) but still don’t feel right. I have a pressure behind my eyes kind of like a dizzy feeling(I have had numerous tests with no answers). I am wondering if this is caused by thyroid. I also feel weak and tired some days. Here are my current labs.
Tsh-0.08. (0.32-4.00)
Free t4-10. (9-19)
Free t3-3.1. (3.1-6.2)
Reverse t3 -8 (8-25)
Thyroglobulin antibody-98. (Under 40)
Tpo ant-570. (Under 35)
Ferritin -74 (5-272)
Vit D -112 (75-250)
Iodine-13. (75-500)
I have been gluten free for 6 months and am currently working with a naturapath. Any advice or insight you can offer would be greatly appreciated. I would like to raise my NDT because my t3 is so low.

Reply
    Westin Childs - September 4, 2018

    Hi Kris,

    If you have any specific questions I’d be happy to try and point you in the right direction.

    Reply
      Kris - September 7, 2018

      Dr. Child’s,
      My main question is do you think it would be best (in your opinion)for me to raise my NDT or just add t3( cytomel) after seeing my labs and hearing my symptoms. Thank you.

      Reply
Barbara - September 5, 2018

I had my thyroid removed 7 years ago and started Synthroid. I always took my pill when I first woke up and about a half hour later had coffee.
A friend told me that wasn’t the correct way to take it. So in January I began taking it when I woke during the night (between 1:30 and 3:30). My TSH dropped to .006. My Dr. changed my 112 Synthroid to 100. I felt terrible — couldn’t fall asleep and when I finally did, I was awake almost every hour, constipated, no energy and continued to gain more weight. I actually couldn’t make it through the day without a nap. But my TSH improved. Couldn’t believe the way I took my medication could change my TSH so much. I am now on 2 pills of Nature-Throid for six weeks. I am sleeping so much better. I still wake up around 1:30- and 3:30 take my pills and fall right back to sleep. I’m not constipated and I am not gaining weight. I go back for more blood work in November and will see my Dr. To be continued.

Reply
    Westin Childs - September 5, 2018

    Hi Barbara,

    Thanks for sharing and I hope you are able to dial in your dose soon!

    Reply
hdxlh19961997 - September 10, 2018

Is it possible that a person can’t tolerate any sort of thyroid replacement? Ndt, T3 etc? My dr has had me on both and said I can’t tolerate any sort of thyroid replacement. I don’t understand this I don’t want to go bald and be miserable the rest of my life! I’ve tried so many doctors and no luck anywhere, my labs aren’t bad just ft3 being 2.3 but everything else seems fine.

Reply
    Westin Childs - September 11, 2018

    Hi Tmw,

    It’s certainly possible but I find it difficult to believe. There is probably a formulation out there that will work for you.

    Reply

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