THYROID - What is Reverse T3

Hi, it's Dr. A. I got another great question, so I thought I would share it in a brief video, and that was generally about thyroid hormone, but very specifically a type of thyroid hormone that a lot of times people don't talk about or test or hear about, and that is reverse T3. So, if you look, your thyroid is synthesized in 4 steps and it's on a tyrosine base and you add iodines. And so, when they say, you know, T1, 2, 3, 4, that's your tyrosine base with 1, 2, 3, or 4 iodines. So, T3 and T4 commonly measured in the blood and they are what are produced by the thyroid for export for the most part. T1 and T2 are— Usually on the inside of the thyroid, working their way up to being T3 and T4, not all the time, but usually. So T3 and T4 are the export molecules, and T3 is actually the most active one. So T4 is sort of a stable form, T3 with 3 iodines is usually deiodinated to T4, 1 iodine taken off in the cell, and it goes and it binds to the receptors. We talked about that in a previous one, but somebody asked, well, what is— I've heard of T3 and T4, but I've also heard of reverse T3, which sounds interesting. So if you think about the manufacture of different molecules, you'll get things that sometimes come out in 2 different ways, and so it's almost like mirror images. So if one T3 is over here and it's normal or active T3 that can bind at the receptors, It's possible for your body to make a mirror image-like molecule. We call it reverse T3, so it can be tested on lab tests. Now, there's a lot of controversy about what it means and all of that stuff, and the research is kind of back and forth, but here's the bottom line with it, because controversy is just controversy, and I don't usually engage in that sort of stuff. In healthy people, reverse T3 may not mean much of anything, like a lot of other things you can test in, you know, lab testing. But in sick people, if you look at, well, why would your body make reverse T3? I mean, it naturally sort of makes some, but sometimes it'll make a little extra. Why would your body make that? Well, we talked about In a previous couple of sections, a long-form podcast and a short form, about my medical treatment made me feel bad or sick or whatever, and I was saying in those that one of the things your body does when you're chronically ill is it keeps your metabolism tamped down so that you can't have too much energy. That's great. Why is my body doing that? Well, it's basically doing that saying, if you're gonna be sick, and your body's not gonna work appropriately. We're not gonna let you operate your metabolism at full speed. So what happens, one of the many ways this happens, and stress hormones can induce this, which are induced under chronic illness, the cytokines of infections, all sorts of things do this. It'll go, and when the thyroid hormone is produced, instead of producing a little bit of reverse T3 and a lot of regular T3, you'll start to make more of the reverse T3. And I used to tell patients reverse T3 is sort of like evil T3. It goes and blocks the receptors. So you have this molecule where if it was turned around, it would be useful, and now it's actually inhibitory. So your body is using this as a protective mechanism. This is why I was saying in the, you know, why did my therapy make me sick sections? Yeah. It's the body trying to do something with you usually being chronically ill or very acutely ill, trying to slow things down. Now, it doesn't mean it's the right thing long-term, but short-term it's trying to protect you. So reverse T3 in a sick person, a chronically ill person, we got to where we measured reverse T3 and all the other thyroid stuff in every chronically ill person. And many chronically ill people, you'll see The reverse T3 is way above the normal index, and that is just a sign that the body is working to try and slow things down so that you're not hypermetabolizing with a really sick body. And so it's literally kind of like if you had engine problems and, you know, you kind of went into idle or first gear and you're okay if you're going slow, but you go fast and the thing's going to blow up. up, your body's thinking that way biochemically. We won't let you go fast because we don't think you have the reserve to do that. So reverse T3 is one of many ways that the— that this slowdown goes in. Now, there are ways to treat it, if you will. Mostly it's an indication of a bigger problem, and so treating the rest of the problems is really the ultimate treatment for it. But also getting the stress hormones and the inflammatory cytokines back in line will bring it down a bit. Initially, if people are supported, sometimes your doctor will give you T3 hormone. Normally thyroid is T4 that you take by mouth. There is a T3 version in a mix, but normally it's given as T4, so your doctor might add some T3 or give you some T3. Normally that's useful in the early phases of treating chronic illness. That's only something that you and your doctor can sort out though, but that's why that's done sometimes. And definitely, uh, giving T3 will bring the T3— reverse T3 down. Now, one of the things that you have to be concerned with though is just like your illness makes you feel bad because you're suppressing your metabolism, if you go in guns blazing and just put a bunch of thyroid into somebody, especially T3, and turn all their mitochondrial and nuclear receptors back on, Their body will speed up, and if, as I was saying, the engine is broken and the engine's going to blow up if we speed it up, that's not going to feel well. There's another reason why treatment can make you feel sick. So you get thyroid even though you need it, even a T3 therapy, and you feel worse. That doesn't mean the thyroid's bad. It means you don't have enough support for all the other problems that are going on. So reverse T3 is a little piece of a very big puzzle. In healthy people, there usually is, in my experience, not a reason to be testing it because they're healthy, but in chronically ill people, there is a reason to test it and also to use it as a marker for how suppressed the rest of that person is, and the longer you've been sick, generally the more reverse T3 you'll build up. Now, is it something where you're just treating that one thing? Yeah. No, that shouldn't ever be done because there's so many other things that come involved, but reverse T3 is an important monitor, especially in a chronically ill person. Now, somebody also asked, well, what about if the reverse T3 is low? And it's one of those lab analytes that if it's low and you're feeling healthy or you're treating it, it will naturally go down. It'll go below There's no harm. It doesn't hurt anything. It's not necessary. It's naturally made in your body, but it will come back after you're done treating it. So low doesn't really mean much. High definitely does indicate this sort of metabolic suppression. So hopefully that helps. You know, like, share, subscribe, notifications, all those good things. Really appreciate everybody and all your comments and questions. Thank you very much. Thank you.