Ask The Pharmacist: Measure reverse T3 and get thyroid healthy

Suzy Cohen

I bet you know how hypothyroidism means reduced level of thyroid hormone. Active thyroid hormone is dubbed as “T3.” But you probably have not heard of reverse T3.  Today I’m going to tell you why you should never ignore reverse T3 testing, even if your endocrinologist does. 

First the basics. The hormone called T3 gives you energy, it’s sometimes called the gas pedal in your body. Reverse T3 abbreviated as rT3, would then be the brakes. You sometimes want the brakes don’t you? Or else your body will speed down the highway and zoom out of control, so rT3 is required as part of the push-pull balancing system. 

Doctor checking thyroid glands of senior woman.

So IMHO, not testing for rT3 levels is an oversight. If you’re rT3 dominant, you’re clinically hypothyroid, stressed, anxious, overweight, tired and cold. The scary part is that your TSH and your free and/or total T4 levels might be in perfect range. How would know you were rT3 dominant unless you were tested. I’m making a good case here aren’t I? 

Thyroid hormone regulation influences your weight and metabolism meaning how fast you burn off that figgy pudding. It is responsible for mitochondrial production of ATP, so ask yourself if you’re tired all the time.

By the way, I have a much longer and comprehensive medical article that gives you much more information about rT3 and thyroid. This version includes ways on how to Lower rT3 naturally and get slim and gorgeous again. I’m happy to email it via my newsletter if you sign up for that at my website  In the meantime, do you have:

Low T3

If you have too little Free T3 relative to T4, you get hypothyroidism. Therefore, you experience weight gain, fatigue, joint and muscle pain, depression, and a tendency to feel cold. 

Blood sample for thyroid panel test

High rT3

Too much reverse T3 and you get the same effects as hypothyroidism (low T3) because the high rT3 blocks the cell’s ability to bind active T3. 

If you have high levels of rT3, I suggest you do not use the T4 drugs (Levothyroxine is the generic), because it tends to break down into even more rT3 (as opposed to T3). As a result, some of you still feel awful and hypothyroid, even though you take your medicine, and never miss a dose. 

What if rT3 is high? What if your TSH is normal but you still feel terrible? I’ve covered this entirely in my book, “Thyroid Healthy.” I’ll nutshell it for you here by recommending that you talk to your physician about switching medications, and use with that contains T3. I think adaptogenic herbs can help, specifically ones that activate T4 to T3, for example ashwagandha.

Human Thyroid Gland Illustration. 3D render

I’d consult the oracle Dr. Google (lol) and learn as much as possible about this little gland. It’s good to bind heavy metals, another cause for elevated rT3. And finally, there are specific B vitamins and minerals, as well as vitamin D that help reduce rT3 and raise free T3. 

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Suzy Cohen is a registered pharmacist. The information presented here is not intended to treat, cure or diagnose any condition. Visit