Armour Thyroid Explained: Who It Helps (and Why It’s So Controversial)

Beyond the Thyroid – Episode 48: Armour Thyroid Explained: Who It Helps (and Why It’s So Controversial)

In this episode of Beyond the Thyroid, Dr. Dana Gibbs breaks down one of the most debated topics in thyroid care: Armour Thyroid and other natural desiccated thyroid (NDT) medications.

Why do some patients swear by it—while others are told to avoid it entirely?

Dr. Gibbs explains the science behind NDT, including how it differs from levothyroxine by containing both T4 and T3, and why this can be beneficial for patients who struggle with T4-to-T3 conversion. She also addresses the reality that 15–20% of patients remain symptomatic despite a “normal” TSH, and why this fuels interest in alternative therapies.

At the same time, this episode dives into the limitations and risks of NDT, including its fixed 4:1 T4:T3 ratio, differences from human physiology, and the challenges of dosing T3 safely.

You’ll also learn:

•  Why stress, inflammation, and nutrient status affect thyroid hormone conversion 
•  Why NDT is often avoided in thyroid cancer management 
•  When caution is needed in Hashimoto’s disease 
•  Why individualized, physiology-based care matters more than any single medication

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Episode Highlights

00:00 – The Armour Thyroid Controversy
00:56 – Thyroid Lab Program Update
02:38 – What Armour Thyroid Is
05:42 – Why Some Patients Improve on NDT
08:48 – T4 to T3 Conversion Explained
11:08 – Fixed Ratio and Dosing Challenges
13:59 – Who Should Avoid NDT
16:29 – Conventional Endocrinology Approach
17:31 – Nuanced Clinical Takeaways
18:57 – Wrap-Up and Disclaimers

This episode offers a balanced, science-based perspective on a controversial treatment—without oversimplification.

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✉️ Email Dr. Gibbs at drgibbs@DanaGibbsMD.com or visit https://www.danagibbsmd.com/ for more information.


Thank you so much for listening! Tune in on the next episode.


The medical information provided in this episode is intended for informational purposes only and should not be construed as medical advice. Always consult a qualified healthcare provider regarding any medical questions or concerns.

Transcript

0:00

Welcome to episode 48. If you have spent any time in thyroid online forums, talk to other patients or even just Googled thyroid medication, you've probably come across arm thyroid and strong opinions about it. Some people swear by it. Many endocrinologists refuse to even consider it. And if you've seen headlines in the past year, you may have noticed it's been in the spotlight since last summer with renewed scrutiny from the FDA and a wave of political controversy that had very little to do with patient care and a lot to do with power influence in industry dynamics. So today on the podcast, I'm gonna break down how I like to think about this class of thyroid replacement medications, what it's uniquely good for, why some people think it ought to be banned, and why the truth is somewhere in between. But before we go further. I wanna update you on my lab analysis group program for patients. Most patients with thyroid problems don't suffer because no one cares. They suffer because the right labs aren't ordered because doctors are busy following insurance rules and outdated guidelines, or their labs are being interpreted in isolation rather than as a part of a physiologic pattern. Medicine really lives in silos today and frequently the only person who sees the entire picture is you the patient. This course, it's called the Thyroid Clarity Checkup, and it's all about thyroid labs. Particularly what patients can learn by getting their own truly complete thyroid panel and knowing what those lab values mean when they get them. So in this program, I taught just that and it was very successful. The patients were very happy. And in the context of different ways thyroid disease can present, including having symptoms, but having your TSH be normal. We went over what that meant and how to get around that. The program went great and I'll be starting a new session in upcoming months if you wanna sign up for priority access to the next session. You can do that at thyroidclarity.com/checkup, and we'll send you an invitation the next time we open the enrollment because normal labs don't always mean normal physiology. All right. Welcome back to the podcast. If you are new here, I'm so happy to have you. If you like what you hear, please don't forget to subscribe and share with your family members and friend who may also have thyroid problems. So what's the truth about Armour Thyroid? So Armour Thyroid is one brand in a class of medications called natural desiccated thyroid. These are made from dried animal thyroid glands, typically pork. Or sometimes beef thyroid glands, and they have been used for over a century long before synthetic thyroid medications existed this was the only treatment for hypothyroidism. Then came levothyroxine. The synthetic T4, it was stable, it was consistent, it was easy to dose. The manufacturers pushed the idea that once daily dosing was fine, and it was very heavily marketed to physicians, particularly academic physicians in position of influence, and that quickly pushed it to become the standard of care. Over time, most endocrinologists moved almost exclusively towards using synthetic T4 and away from the desiccated thyroid products. But here's where things got complicated. So natural desiccated thyroid contains both T4 and T3, and these are the two primary thyroid hormones as your own thyroid gland is supposed to make. And for some patients, especially those who feel not so well if they take levothyroxine or T4 only containing thyroid medicine that matters a lot. This is why you'll find a growing number of patients and practitioners who believe desiccated thyroid is much closer to what your human body actually needs. At the same time, there are legitimate concerns, these products can vary from batch to batch. The T3 content is relatively high compared to human thyroid output, and once daily dosing is a big problem for some patients that can lead to symptoms of Overtreatment, palpations anxiety, bone loss risk, especially if it's not carefully managed. So we've got these two extremes. One side is saying, this is outdated and unsafe. The other side is saying this is the only thing that works. And as usual, the truth is more nuanced than either side is willing to admit. So today I'm unpacking what Armoured thyroid actually is, who it might help, who it might not, and how you wanna think about that in a way that's grounded in physiology and not ideology. Because this isn't about choosing sides, it's about choosing the right treatment for the right patient. So let me tell you about a very typical patient of mine. She came to me after years of being told her labs were fine. She was on levothyroxine. Her TSH was normal. Her T4 looked fine, and yet she was exhausted. Her hair was falling out. She had gained weight that wouldn't budge despite a previously active life and mindful eating. She found her mind wasn't as sharp as her demanding career continued to require, and this was despite getting on menopausal hormones. The kind of symptoms that start to affect not just how you feel, but how you function in your life. And at some point, she found her way to me and it turns out for her armour, thyroid was the right answer. And that's where this confusion can come in, because why her and not the next person and why did she even need thyroid medication if her TSH was normal? The biggest misunderstanding in this entire conversation is that this is a debate between medications. It's actually not, as you may have guessed, I am agnostic when it comes to Armoured thyroid. There are people for whom it absolutely works the best and for others for whom it is absolutely not recommended. It's a question of their physiology, and it's not really about the Armour itself, it's about T3. So levothyroxine is T4. T4 is a naturally occurring hormone in the human body, just like insulin is. The fact that levothyroxine is synthetic doesn't make it bad. It's a life-saving medication just like insulin is. But T4 is the storage form of thyroid hormone. So levothyroxine is available in various brand names and generics, some of which are better quality than others. Some have been shown to be very tightly adherent to the amount of hormone that's listed on the label, and some of them can vary up or down by 20% or more, and that's just the ones that aren't bad enough for a recall. They can also be legally contaminated with reverse T3 because the FDA believes. I'm not so sure that reverse T3 is an inactive metabolite and it doesn't matter. The various brands and manufacturers can also use any number of different additives or excipients and artificial colors in these medications just the same as any version of any other drug or supplement can. So this is one argument that endocrinologists use to argue that levothyroxine is uniformly good. While"pig thyroid", as they call it, is not, and that's that it's tightly regulated and uniformly pure, but it's actually not much better or worse than any other medication, but in my hands, the brand of thyroid medicine, whether it's levothyroxine or something else, absolutely matters. Here's the thing. T4 that's in levothyroxine is the pre hormone. It is destined to be either converted into T3, which is the active hormone your cells use, or broken down if there's too much hanging around. So when somebody takes T4, their body still has to do the work of converting it to T3, and that conversion is not guaranteed, and it's subject to lots of factors that don't necessarily help us stay healthy in the modern world. Conversion depends on genetics. Stress and cortisol, inflammation, nutrient status, sleep, metabolic health. If any of those systems are impaired, the body may produce less active T3 and more reverse T3, which slows things down even further, and this turns out to be important in several situations. The first one is that 15 to 20% of people who are taking levothyroxine don't feel well even with their TSH normalized. And studies show that these folks in general do not have the same relative amount of T3 in their system, that healthy people in the same TSH range have. The second is that people who have only mildly abnormal or even normal TSH, can still have trouble converting the T4 that they already have enough of to active T3 to feel well, this was the case with my example patient. Her T3 was quite low, even though her TSH was not elevated. Her T4 before the levothyroxine had also been in the lower end of the range, but just adding more T4 to her system lowered her TSH even more. But made her T3 numbers worse, and I've talked about why this happens in episode 34 of this podcast. So when she takes Armour thyroid, she's getting now T3 and T4. So she feels better, not because Armour thyroid is natural, but because it contains the T3 and T4 hormones in a ratio that is correct for her. So Armoured thyroid contains both T4 and T3, and it's in a fixed ratio that comes from animal thyroid. And this ratio does not match human physiology perfectly. So this is another argument that endocrinologists use to condemn this entire class of medications. The ratio in Armoured thyroid and its brothers is four to one t4 to T3, where human thyroid glands release about 10 T4 to one T3. This means humans are more dependent on conversion to T3 than animals are. Now, this is only my guess, but animals do not have the ability to make fire or shelter or use blankets to stay warm. So they have to expend more baseline energy than humans do to survive cold temperatures. And I think having that fixed amount of T3 higher helps them do that. So some patients do extremely well with that ratio. If they don't convert T3 well enough in the first place, other patients may feel overstimulated and when the only test their doctor is using to monitor their thyroid treatment is TSH. Figuring out whether the dose is too much, not enough, too little can be a big problem. And some people are actually so bad at converting T4 that they need more T3 than Armour Thyroid provides, particularly if they weren't very low on T4 to begin with. T3 when it's produced naturally from T4 in your body is produced in a tiny, steady amount like two micrograms an hour all the time. Same. So when somebody takes a T3 containing medication, your body absorbs it all at once. It goes way up. The levels go really high, it acts quickly, and then it wears off until the next dose. And if the dose or the timing isn't right, patients are gonna feel jittery, anxious, irritable racing, heart wired up. And then as it fades down, they'll feel just the opposite until the next dose. So the issue is not whether it works, it's that dosing it the same way we dose and monitor. Levothyroxine does not allow for fine tuning. So when I use separate doses of synthetic T4 and T3, I can adjust the amounts of those independently. With Armour, you're locked into that same ratio, four to one. That's all you get. So again, it's not about good versus bad, it's about flexibility. There's a final thing about desiccated thyroid products that give me pause and that's the actual fact that it is a natural product. It is made of whole thyroid glands from animals. Whole thyroid glands contain the proteins, thyroid globulin, and thyroid peroxidase, and there are two reasons why I wouldn't wanna give that product that contains those proteins to a specific patient. The first one is thyroid cancer. In the regular monitoring of a patient who has had their thyroid removed because of differentiated thyroid cancer, like papillary thyroid cancer, one of the ways we decide who has had effective treatment and who might be experiencing a recurrence is by following the blood levels of thyroid globulin protein. And if that number stays close to zero, we're pretty sure the patient is not having a recurrence. They're all good. Giving that person any whole thyroid gland extract at all would invalidate this method of monitoring their cancer. So I can't give it to somebody who's had thyroid cancer. The second is autoimmune thyroid disease. So since Hashimoto's disease is the most common reason for a person to need thyroid medication, this is a very large if theoretical risk. So the two thyroid proteins that drive the main antibody reactions in Hashimoto's disease are, you guessed it, thyroid globulin protein and thyroid peroxidase protein. You can probably see where I'm going with this, right? Why would we want to give more of the proteins that could potentially accelerate the attack on the thyroid gland, or at least increase their antibody levels since this is theoretical rather than proven. If somebody needs thyroid medicine and has low antibody levels. We can use shared decision making to decide whether the additional convenience of only needing one prescription is worth the additional risk for that person, and then potentially monitor their antibody levels for a while to see if they go up. But in general, I tend to lean towards using a combination of synthetic T3 and T4 for patients who have Hashimoto's, particularly with high antibody levels. The real divide is not the medication, it's the treatment model. So why do so many endocrinologists avoid Armour Thyroid? Part of it is legitimate. It's concerns about consistency, T3 effects monitoring complexity and long term safety. But part of it comes down to how thyroid disease is approached. If your entire model is normalize. The TSH, give TT4 and you're done. There is no reason to use a more complex medication. But if your model is, does the patient actually feel well? Is there enough active hormone at the tissue level? Then you start asking different questions, and sometimes those questions lead you towards including T3 in some form, whether that's a desiccated thyroid product like Armour, or a combination approach. So this should not be just a medication debate, it's a philosophy of care. So where does that leave us? Armour thyroid is not a miracle drug and it's not a dangerous relic properly used and monitored. It's a tool for some patients. It works really well for others, not so much. And the key is understanding why. If somebody improves on Armour, it tells us something important about their physiology, especially about the T3 availability and their ability to convert T3. But it doesn't mean it's the only, or even the best long-term solution. So my goal is not to pick a side that is a false debate. My goal is to choose the right approach for the patient in front of me. So if you imagine, instead of being told your labs are fine, when you still don't feel like yourself, you actually understood what those labs meant, what the breakdown was, and what your options really were. This is the kind of detail that we go through in my lab analysis course, the Thyroid Clarity checkup. We'll look at what your labs actually mean, where there's room for improvement, and how to think about the various treatment options that you have in a much more individualized way so you can find more information about that next session of this course@danagibbsmd.com slash checkup, because that kind of clarity changes everything. Thanks for listening, guys. I'll see you next week. Thank you for listening to this episode of Beyond the Thyroid. If you found this information valuable, it would mean so much to me to take a few seconds and give the podcast a five star review. It helps other people who need this information find the show and it's really easy. Just search and click on the name of the show, Beyond the Thyroid, and scroll to the bottom to ratings and reviews. I truly do read and appreciate. Remember, when it comes to hormones, there will always be more to discover, so follow the show so you get the next episode as soon as it's released. And if you or someone you care about needs a caring doctor to help figure out how to heal hormone problems that other doctors have dismissed, check out my website at www. danagibbsmd. com. And if you're not a physician, please keep in mind, while I'm a doctor, I'm not your doctor. The content of this podcast is my opinion and it's for educational and entertainment purposes only. This is not meant to be individual medical advice and you should consult your own physician for any medical issues or diagnoses that you may have. I look forward to continuing this journey with you beyond the thyroid.