What is Reverse T3?

What the heck is reverse T3? T4 can go down the reverse T3 pathway instead of the active T3 pathway. If you are in a stressful condition, sometimes conventional doctors will measure it. In situations like the patient is in the ICU, your reverse T3 is going to be really high if you're in the ICU because it comes, it gets produced under times of physical stress, physical, mental or emotional, all that chronic cortisol and adrenaline production, any kind of physical trauma to the body, a consistent low calorie diet can cause elevated reverse T3. Just calorie restricting is not good. That is how your metabolism ends up getting turned down. And the weight that you have lost by being on your low calorie diet all of a sudden comes back and you regain that weight, and probably more than that, because reverse T3 is having the opposite effect on your cells. It's sending the opposite signal of active T3. So reverse T3 says, slow down your metabolism, stop growing your hair, stop nourishing your skin, slow down the bowels, so you end up with hair loss, constipation, weight gain, feeling cold all of the time. Like all of these hypothyroid symptoms when you could have a normal TSH, a normal T4 and normal T3 level in your blood almost, they're not going to be optimal, but they're going to be normal by conventional standards when your reverse T3 is elevated. So like I said, this is elevated from multiple things, even infections, kidney dysfunction, liver dysfunction, medications, alcohol use, all of that. So as a functional doctor, I love checking reverse T3 because to me, that is a marker of systemic inflammation, toxic burden, thyroid dysfunction. If it's over 15, we have some work to do, we really gotta start working on some stuff.