14: Struggling with Thyroid Medications? The Shocking Truth About T4 vs. T3 with McCall McPherson
16 Dec 2024 · 28 min
McCall McPherson breaks down thyroid medications: T4, T3, natural desiccated thyroid, and compounded options. Many people stay symptomatic on T4 alone, but adding T3 helps. TSH and T4 labs can be misleading once you're on treatment, and T3 dosing twice daily carries overmedication risks.
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Welcome to Modern Thyroid and Wellness, the podcast that explores the intricate dance between health, wellness and thyroid, unraveling the threads that weave our vitality together. I'm your host, McCall McPherson, and I'm so thrilled to guide you on this journey to optimal wellness. Today we are demystifying thyroid medications. We are going to talk about all the various types of thyroid medications. My favorite types, when I use each, when I stay away from each, how to potentially choose the right one for you. So let's dig in. You all know, if you've tuned in to much of my other content, that I am an enormous advocate for T3 based medications. What does that mean? There are two types of output hormones that our body needs for fuel in terms of your thyroid. One is T4. T4 is an inactive hormone, has to be activated, it's inert until it is. I give an analogy of crude oil, right? Like we don't put crude oil in our car to make it run, but we need it to make gasoline to put in our car to make it go. If we can't convert that crude oil to gasoline, we're not really going anywhere in our car. So T4 meds are crude oil and active meds. And unfortunately for many people, they are essentially what is ubiquitously offered to patients in our country, but also essentially worldwide. The other type of thyroid hormone medication is T3. So T3 based medications are active. They are already in their usable form as fuel to your body or gasoline. Right? They are the active form of thyroid hormones. They are not dependent on your ability to convert them. So definitely two important, both very necessary hormones. But you know, each one has sort of limitations and pros and cons. For the last, you know, half century, we have been relying on T4 inactive or levothyroxine based medications to treat thyroid. We did that because we view them as more stable, longer acting. If you were to stop levothyroxine today, half of it would still be in your system in a week. So very, very long acting stable medic. And that is all well and wonderful and actually super useful if you can activate those medications. But the number one reason people on levothyroxine based medications still have thyroid symptoms is because they can't. So we're going to dig in deep on these topics today. Let's talk about first the two classes or a few different classes of medications. Right? Number one is T4 inactive or levothyroxine based medications. These include drugs like levothyroxine, obviously Synthroid, lubricant, unithroid, Levoxyl, that's one class. Second class is the opposite. It's pure active thyroid hormone or T3 based medications. These drugs are called lyothyrenine and Cytomel. Okay, so that's just simply a brand versus generic. Cytomel is the brand name version, Lyothyronine is the generic form. These are the only form of pure T3 available. Okay. Then we have combination medications like natural desiccated thyroid, sometimes referred to as NDT. And these are medications that are largely T4 or heavier on T4 and then also additionally have some active hormone or T3. These drugs are Armour, NP, AD, FISA, who is rebranding and coming out with a new product in 2025. These drugs are combination, okay? And they come from pig thyroid gland. That's why they're referred to as natural. They are not synthetic. Prior to these drugs, all the other medications we've referred to Synthroid, Levothyroxine, Lyothyron, Cinnamon, these are all synthetic drugs, meaning they are manmade like most medications. NDT comes directly from the thyroid gland of pigs. Okay. The last class is compounded. So generally compounded drugs are a combination of T3 and T4 and they are put together and they are sustained release. So this could be synthetic, which it usually is. It could also be compounded, you know, armor or np, that kind of thing. And we'll dig into pros and cons and limitations of those. So let's talk first about the T4 based meds. Levothyroxine based meds, we touched on this a little earlier. They are completely inactive. They are not usable in your physiology until you activate them. A lot of things influence the activation of your thyroid hormone. So this is where things get challenging. Okay, so pros of these meds are again, like I mentioned, they're very stable, they're very long acting, they don't swing right. Cons are your body tends to halt the activation of your thyroid hormones in a lot of situations, especially a lot of situations that are very common and normal in standard American lifestyle. So I believe that there is a degree of poor activation or conversion of T4, your inactive hormone inherent in most people's lives. Okay. Things that influence this, I want you to understand the physiology. Things that influence this are things like things that stress your body, that make your body want to go into recovery. So you're sick, maybe you're micronutrient depleted, maybe you aren't getting enough calories or protein, maybe you're over exercising, maybe you're inflamed maybe you're not sleeping well, maybe you're stressed from work or family or traffic. You know, pregnancy also does this, your body, on purpose, y', all, halts the activation of your thyroid hormones so that you lay down, you rest and you recover. So you repair the mechanism that's creating this environmental stressor on your body. The problem with that is we are all walking around a little stressed. Most of us are walking around a little bit inflamed, Most of us are not getting adequate micronutrients and enough sleep, etc. So we are essentially offering the world, really, I mean, I can say America, but we are offering the world a medication. Only one class of medication that is dependent on their ability to activate it. Well, to make it usable. Okay? And I can tell you from my experience, day in and day out at modern thyroid clinic, a huge percentage of people do not activate these medications. Well, does not matter how much crude oil you give someone, if they cannot convert that crude oil to gasoline, their car is not going anywhere. Okay? So that's the deal that we have to live with. And medicine has yet to recognize this. They simply believe that if someone has thyroid symptoms, they have a diagnosed thyroid problem, they go on levothyroxine, they take it and they don't get better. It's because their symptoms aren't their thyroid. It has nothing to do with their thyroid hormones. Additionally, the problem with T4 meds is we are looking at labs only in the form of TSH or maybe TSH and T4. Well, if you are on a T4 based medication, guess what? Your T4 is going to look awesome. And the worse you are at using your levothyroxine based medication, the better your labs will look. If someone is only checking your TSH and your T4 because you will have all this inactive hormone, all of this crude oil stockpiled in your garage, not converting to gasoline because you are a poor converter, which will make your T4 look. What? Oh my gosh, you have so much T4, it looks amazing, which will in turn suppress your TSH and also make that look amazing. So what your doctor, your clinician will tell you is, I checked your thyroid labs. Your thyroid labs look great. Your fatigue and your brain fog and your weight gain are not due to your thyroid because your thyroid numbers look awesome. However, they are not checking your active hormone, your most important thyroid hormone. So the big picture on T4 based meds, and I preach this a lot, is if you are on a T4 based medication, it is impossible to gauge the status of your thyroid function by checking your TSH and your T4 alone. It is impossible. Okay, so my practice is filled. In fact, a hundred percent of people at modern thyroid clinic are poor converters. Either they can't activate and convert their own endogenous T4 or crude oil hormone or they can't activate their levothyroxine. So and we, you know, we have a fraction of the people on these meds, but if you are out there and you are on levothyroxine and you are still having symptoms, this is why have a whole YouTube dedicated to why Synthroid or levothyroxine doesn't work. So you might want to check it out. So that is T4 based meds. Let's talk next about T3 based meds. What are the pros of this? Well, T3 based meds are active. They don't need to be activated at all. They are pure active thyroid hormone. Right. They are all essentially gasoline with no crude oil which can provide your body with exactly the hormone that it's probably missing that's causing your thyroid symptoms. So big, big opportunities here. Very important hormone, incredible medications. The limitations of these meds are one most prominently, clinicians are not trained how to use them. So we are trained to only use T4 or inactive hormone based medications and we're trained not to use T3. And we're also trained to be very afraid of them despite them being really darn safe. So it's difficult to find someone who A is willing to put you on these meds and then B, effectively knows how to use them because it is nuanced. Okay, so that's the biggest limitation. Second is they're very short acting. So cytomel, Lyothyrenine is it peaks and troughs in someone's bloodstream in about three to six hours, which means they need to take it multiple times a day, which is a commitment. But honestly, once people get into that rhythm, they feel so good they don't care. But still, it is a limitation. Another limitation is people don't know how to adequately check labs to time your medication on how to take it before you get your labs drawn. So again, a lot of this is educational limitations which I am really going to be working on trying to change. And I already have, if you guys are familiar with my content. Other limitations with lyothyrenine or downsides or cons to it, these meds are very safe, very effective. But if you walk around with a lot of extra T3, it can actually increase your chance of heart attack and stroke. So a lot of medicine is afraid of these meds. A lot of medicine doesn't want to use them. And in reality that those things are possible, but it's very hard to do. You have to honestly basically not know what you're doing, be medically negligent. But it can happen. And I will tell you, for the first time in my career, I actually see this becoming a pervasive and consistent issue. Okay. People are transferring to modern thyroid clinic from other practices. Generally it's online and their T3 is like 30. It's above 34, which is crazy, y'. All. Our range is 3.6 to 4.2 for the bulk of someone's day. The upper limit that a lab can detect is 34. And we are seeing people reading above that and that's, you know, I won't go into all the details, but for the first time ever, I'm seeing it reasonably consistently that people are so grossly, negligently over medicated that it actually is dangerous. And that is again, that is hard to accomplish. It's a big undertaking to get someone there. So outside of kind of these people who are advocating for high doses of T3, checking labs off meds, it's really hard to get there. But again, people are now advocating for those things and it's actually happening. So you guys need to be careful and attentive because While I view T3 as being extraordinarily safe, it is now being used in unsafe ways very frequently. Another downside to lyothyrene is of all the T3 medications, it increases and decreases quite quickly. And that can cause people to feel more sensitivity to this medication. They can have a little anxiety or a little palpitation when they first start, especially a little jittery over caffeinated feeling. Most of the time that's fine and it's self limited and it goes away and resolves on its own. But if people are sensitive to that, they're kind of a little more prone to that with a lyothyonine, certainly as compared to levothyroxine. Let's move on to natural desiccated thyroid. So natural desiccated thyroid is again pig thyroid gland that is broken down into a combination of T4 and T3. Together we cannot skew that ratio of how much T4 or inactive compared to T3 that we are getting because again, it is pull pig thyroid gland. Okay, so pros and cons of these meds. Pros are I love this class of medication. I absolutely have favorites and these meds changed my life. They absolutely gave me my life back from my own personal thyroid crisis. I use them very frequently with patients, but they do have limitations. Other pros of them is their T3 peak in trough is a little longer than leothyreneine in your bloodstream. It's more like six to eight hours as compared to lyothyrene. I still dose these meds twice a day, y'. All. It is so important if you are taking any T3 based medication that you talk with your clinician about twice a day dosing. I give my patients morning and late afternoon like 2 to 3pm for twice a day dosing so that you can occupy your entire day or the bulk of your waking hours with appropriate levels of T3. This is important for hormones, for energy, cognition, hair, skin, digestion, metabolism, all the things cons of these medications. So cons are the transition. Like let's say someone's on levothyroxine and they want to go on armor. The transition to do that. Often people get worse before they get better because there's a very different half life situation happening. A lot of clinicians don't know how to transition them. And so either they will be undermedicated, under dosed and not end up on a good amount of armor for example, or the transition is quite volatile. And this is classically what happens on a Monday. Someone stops levothyroxine, let's say 100 micrograms of levothyroxine and their doctor converts them over to co quote an equivalent dose of armor, which really is inaccurate. But this is how people do it. And they stop that on. They stop Levo on Monday, they start armor that Same day on 60 milligrams of armor. Well that 60 milligrams of armor has a lot of T3 that immediately goes into your system, very short acting and that levothyroxine is not out of your system. Half of it is out in seven days. So now we have effectively doubled your dose of medication in one day. And that's uncomfortable. Most people feel really anxious, they feel really agitated, they have palpitations, they feel jittery and they think that they have a problem with armor, Thyroid for example, they can't tolerate it. Well that's not true. That just was completely dosed wrong and you got way too much medication in one sitting. So essentially the transition from levo to armor is a tough one and I actually don't recommend it even for clinicians that are practice at modern thyroid who are extremely Seasoned. I will talk more about later, what I recommend in those situations. So that's one limitation. The other limitation of armour is the RE or NDT, I should say armor, ADISA, NP and then ADISA's new, newer medication that's coming out soon. The bulk of These meds are T4. The bulk of them are inactive hormone. And so you have to have adequate enough conversion to handle the ratio of inactive as compared to active hormones in these meds. And not everyone can do that full stop. And so, you know, the other thing I want you guys to know about desiccated thyroid or NDT is people online have this whole propagation of this concept of these drugs are better because they're natural. People feel better on these drugs because they're natural. And listen, guys, I am a functional medicine practitioner. I am appreciated natural integrative methods. The reality is this, guys, these meds are not better because they're natural. These meds are better because they have T3 in them. Okay? T3 is light years better than T4. So if you want to compare it to levothyroxine, do I think it's better? Heck yes. If I want to compare NDT to lyothyrenine, it definitely has pros, like the, like how long it lasts in your system, et cetera. But naturals not doing it. It is T3 that is helping change lives. Another limitation of these meds are they are again, very, very misunderstood in medicine. We are trained that desiccated thyroid is unstable, unreliable, unpredictable, and some forms are like some of these. I don't use some brands of these meds because of that. But let me tell you guys, in the beginning, these meds were the first drugs that came out to treat thyroid dysfunction. They came out in the 1920s and until about 1980s, early 80s, they were unstable, they were unpredictable and they were unreliable. Guess what? In the early 80s, we solved that problem. These, you know, armor, for example, is very stable, very predictable, very reliable. But medicine is still holding on to this idea that it's not because of everything that happened before 1980. We have not updated our view of these meds since then. I do think 2025 is going to bring change in that realm. There are very, very exciting things happening in the world of natural desiccated thyroid. And I am going to be on the ground floor to try to change the conversation and the beliefs around these meds and educate clinicians how to safely use them, educate them on that they are safe, predictable, controllable, with finite, like, with very measurable predictability. So anyway, very, very exciting things happening here. But medicine needs to update its view on these meds. And until they do, people don't know how to use them. Again, they're very afraid of them. They think they're going to cause a heart attack, and they're not going to be stable. Again, people also are not standardizing ways to measure labs after people are taking meds. So there is no standardization of how do I take my armor before I get my labs drawn? Okay, how do I take my np? How do I take my adisa before I get my labs drawn? No one is actually doing a good job of figuring that out. And so, again, it reaffirms this belief that these drugs are wildly unstable, because sometimes people are checking them on meds, sometimes they're checking them off meds. There is no standardization, which is so important. You guys hear me advocate for this all the time. Let's talk about compounded meds. Compounded meds are something that I refuse to use at modern thyroid clinic, okay? I use compounded meds with hormones all day, every day. But with thyroid, it is not a winning game plan. And I'll tell you my experience and why I believe that, and I'll give you an analogy Alan Christensen gave me many, many years ago. When you are making muffins and you are trying to get an even amount of blueberries in all of your dozen muffins in each one, it's kind of possible, right? You can count out those blueberries. You can really get pretty darn close. And that is compounded meds in terms of making drugs that are used in milligram doses. When you are making drugs in microgram doses, which is what thyroid meds are made in, you are making muffins, trying to put an even amount of poppy seeds in every muffin. And you know what, guys? It's not going to happen. And in at modern thyroid clinic, what makes us better than everyone else at doing our job is we control every variable. We create predictability and control with dosing. We understand what's going to happen with someone's labs when we are making medication changes three months from now. We know what will happen with people's labs with compounds. We don't have that. Because you know what? You are not getting the right amount of hormones in your compound. The vast majority of time, you are not getting an even amount of poppy seeds and all those little muffins, okay? And so what ends up happening is life's going okay? Your dose is pretty close to where it needs to be. You pick up a new dose, it's completely wrong. You have a 90 day supply of a dose of medication that is 90, not right. And then I see you three months later and your TSH is 12 all of a sudden and you've been stable for three years. That's an example of the last patient that I had on a compound in 2018. I took them off and I haven't used one since. It makes a complete loss of predictability and control of thyroid medication because again, you don't know what the actual dose that that person is on in reality truly is. So I highly, highly, highly discourage compounded medications. Even if you know they're like, well, T3 short acting lyothyrenine. Short acting. We need to make it long acting, no, dose it multiple times a day, retain predictability and control of thyroid. It is ground zero for creating a long term plan that's going to work for people. Let's talk about some nuances in medication and which one is right for which person, in which case. So let's talk about the most common situation. The most common situation for someone already on a thyroid med is that they're on levothyroxine Synthroid, a T4 based MED, and they come into our office with those people. The vast majority of times we simply add cytomel or lyothyrenine to their existing medication. So they have plenty of T4, they have plenty of inactive hormone, but they need more active hormone. We simply plug that in and that's that in some cases, people might need a little more T4 or a little and a little more T3 in addition to their levothyroxine. And they might like the idea of going on a natural form of thyroid hormone. And then we can slowly, over multiple treatment cycles, not all at once, integrate them onto a form of natural desiccated thyroid. Okay. But the vast majority of time we simply add in the hormone that these people are missing in the form of T3 and in the form of cytomel and lyothyrenine, because that is often the shortest path to people getting their life back without risking them getting worse before they get better. And those are our two main goals at a first appointment at modern thyroid clinic. What can I do to never risk you getting worse before you get better? Today is ground zero. We build up from here. And two, what is the shortest path that I can implement now that will get you to perfect thyroid function as quickly as possible? Again, this is all per patient, it is unique. And also we want to take in to account your goals, your desires, how you want to do things. Right. We view our patient clinician relationship as you are the boss, we are the facilitator. So that we do things in a way that makes you most comfortable and happy is very, very important to us as well. Let's talk about when we would use only lyothyrene. And this is generally when people are naturally poor, poor converters, they come in, they're producing enough T4, they're producing enough of their own inactive hormones, but they're not converting it well enough. And those people need just active thyroid hormone to supply their body with enough T3 to thrive and feel good and have a metabolism and quality of life, and also to feedback and create balance with their inactive hormone, their inhibitory hormone, or what's called reverse T3, et cetera. Now, when would we use natural desiccated thyroid? So we will use natural desiccated thyroid in almost any case where someone needs additional both T4 and T3, most especially if they come on and they're not on any thyroid medication. Right. We love desiccated thyroid. We also recognize it's not a one size fits all. Like there is no one medication that works for everyone for thyroid. It is based in your unique biochemistry and what your physiology needs to attain, I mean perfect, perfect thyroid function. And that's what we're going to do. I also do like to incorporate some, maybe not even all, but some desiccated thyroid in people post thyroidectomy, because desiccated thyroid has a couple little CO factors in it that synthetic meds don't have. That I think can be a little bit of an advantage when people don't have a thyroid gland endogenously. When I wouldn't use desiccated thyroid is when someone's on no meds and their TSH is 18. Right. We have a long way to go. It's harder to reduce someone's TSH quickly in a way that doesn't make them overstimulated without using levothyroxine. And so we like to harness the power of levothyroxine to reel in a TSH quickly and effectively and it doesn't cause symptoms of palpitations, anxiety, overstimulation because it's all inactive thyroid hormone. So there's sort of this delicate balance in cases of really, really elevated tsh. The higher someone's TSH is, the more prone to symptoms of over stimulation palpitations, that kind of thing. They are when they first start any form of T3 treatment. So we always Keep that in mind as well. Some other considerations that we think about when we're choosing a medication dose are age, you know, cardiac history, that kind of thing. A lot of that depends, you know, dictates how quickly or slow or conservatively we will go when we're starting a medication. Those are really, really important things. And then over and above all, we take into account and choose a medication based on a person's goals, wants, desires. Right? That is so important to us. And I want to re emphasize there is no one size fits all, guys. There is no one medication that works for everyone. No, not everyone can go on armor. No, not everyone can just be on Cytomel. It has to be attuned to your specific biochemical needs. So I hope that that helps. Oh, and then, of course, let me back up. When do I use compounded drugs? Never. I never use compounded medication. There is no indication in the world that I would be open to using compound meds for. So I hope that was really helpful. If you guys enjoyed this, please, please, please, please, please go. Leave us a review at your favorite podcast platform. We are just getting this little podcast started and we could use it, share this with a friend. Even downloading this episode, y' all helps us so much. Not simply streaming it, but downloading it. So if you can do that, I would be eternally grateful. And I'll see you back here next week. Don't forget to subscribe.
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