Reverse T3 Dominance is not tested by most doctors and is a huge contributing factor to what is going on with weight gain, hair loss, fatigue and more.

Understanding T3 Dominance and your thyroid.

The below information is a combination of what I learned throughout the last 10 years of healing my thyroid as well as content from these Functional/Integrative doctors: Amy Meyers M.D., Mark Hyman M.D. and Aviva Rohm M.D., who I admire and agree with on many levels. Click on each of their names for more information on the thyroid.

We’re picking up today after Part I and Part II so please read those parts before you read this article so that all of this thyroid information makes sense to you. There is a wealth of information there.

What is Reverse T3 Dominance?

Today’s topic is Reverse T3. I cannot even begin to tell you how important getting your Reverse T3 tested is. The majority of doctors DO NOT EVEN KNOW WHAT Reverse T3 is. Crazy! Right? It took me years to find a doctor who actually understood how to order this blood test and how to read it and analyze it and give me suggestions on what to do. It’s mind blowing that Western doctors don’t understand Reverse T3. I remember going to the best Western medicine doctors all over the country and I’d beg them to test me for Reverse T3 Dominance and they had no idea what I was talking about…OR they would say “Okay, I’ll test you for that” and then when I got the results back, they didn’t test for it because they didn’t know how to interpret it or how it related to what was going on inside the body. So sad and quite frustrating.

I have so many clients who have thyroid issues and don’t even realize it because their doctor never tested their Reverse T3, which is a KEY factor in determining what is actually going on inside your body, especially with your thyroid. Let me tell you a little bit about Reverse T3 so that you know how to order this from your doctor and so that you can take your health into your own hands. When you have hypothyroid symptoms and all the other lab tests appear to be normal, it’s important to test for Reverse T3 so that you can see what’s really going on and assess your thyroid function.

Reverse T3 is made from T4, just like T3 is. As you recall from Part I and Part II, T4 becomes T3 when one of its outside iodine atoms drops off. But, T4 becomes Reverse T3 when one of the inside hormone atoms drops off.

When your body wants to hold on- instead of burn energy, your body takes the active T3 and makes it into this inactive ‘Reverse T3’ form. This can happen when you’re under lots of stress, restricting calories and if you have an infection or a cold with a fever (as noted below).

Reverse T3 is similar to T4 in that it’s inactive and doesn’t bring energy to your cells. So, what does it do?

It attaches to the receptors inside your cells where Free T3 would be. If Reverse T3 is there, that means there is less room for Free T3. This is how your body regulates the quantity of Free T3 in your cells. Reverse T3 is what slows everything down so it’s important to measure your Reverse T3 as well as the ratio between Reverse T3 and Free T3. These tell you what’s going on inside your little baby cells.

How does Reverse T3 Dominance affect Weight Gain?

It’s helpful for you to know what increases your body to create more Reverse T3 so I’m going to share a few things that I’ve learned so that you can be mindful of these points and make sure to avoid them at all costs. What many people do not realize (and what I did not realize for years) is that the below bullet points can ALL cause weight gain and your reverse T3 dominance. Who knew? We were all taught to eat less calories, work harder at our job, workout at the gym everyday and eat more salads to be healthy. Interesting how that advice all backfired for me and for everyone else with thyroid issues. Look beyond just taking a white pill to correct your thyroid issue and focus on what is causing your Reverse T3 Dominance so that you can address the root cause and heal your thyroid. If you don’t and if you continue to push yourself and just pop pills, something else will appear “out of nowhere” in a few years and you’ll be stuck with numerous health issues that you can’t resolve because you’re too much in the hole like I was.

  • Stress. This includes emotional stress (something I went under as a child and again with my college boyfriend breakup), physical stress such as working out too much and mental stress such as working too much in the office!
  • During Infections.
  • Sick with a fever.
  • Exercising Too Much. Your body thinks it’s in a threatened state.
  • Low Calorie Diets. Your body thinks it’s starving and retains fat!Restricting calories will cause this big time!
  • Heavy Metals. Here’ lead, mercury, arsenic and cadmium are very toxic to our body and can really negatively effect our thyroid function. Check out my How to Start a Heavy Metal Detox information and Common Heavy Metals Making You Sick.

When we take a look at Hyperthyroidism and Hypothyroidism, we see that our thyroid can be unbalanced and there are a ton of causes for each one. Here are a few that I come across with many of my clients. These are also a few of the reasons for why I got Hypothyroidism.

Nutrient Deficiencies. There can be numerous deficiencies such as all the B vitamins and vitamin D, which are needed to regulate your metabolism and your hormones. Also, selenium, zinc, iron and vitamin A all need to convert T4 to T3 so it’s imperative that you have enough of these nutrients in your body. Lastly, you need iodine (mineral) and tyrosine (amino acid) in order to create your thyroid hormone. Check with your Functional M.D. before starting any of these supplements.

Too Much Exercise.

Toxic Burden. See my How to Start a Heavy Metal Detox information and Common Heavy Metals Making You Sick links above.

Not Enough Sleep.

Infections (chronic, low-grade infections). Check my Lyme Disease information.

Eating inflammatory foods as well as foods that you’re allergic to or sensitive to. See my book Eating Clean and my anti-inflammatory foods grocery guide information.

Adrenal Fatigue. See my Adrenal Fatigue information.

Leaky Gut. See my How to Heal Your Gut Solution Program as well as my Leaky Gut information.


Next, we’ll be talking about your Adrenals and how they come into play with your thyroid health in Part IV participates in various affiliate marketing programs, which means we may get paid commissions on editorially chosen products purchased through our links to retailer sites.

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  1. “When your body wants to hold on- instead of burn energy, your body takes the active T3 and makes it into this inactive ‘Reverse T3’ form”.

    Would it not be more correct to say the body takes T4 and turns it into rT3 rather than free T3? Otherwise, it would not make sense taking T3 only as some patients with rT3 dominance do.
    Otherwise, a very interesting article.