Reverse T3 and Low Body Temperature: The Connection in Dr. Wilson's Writing

Reverse T3 has become a popular thing to test for, and people arrive here having been told their “rT3 is high” or their “T3/rT3 ratio is off”. Dr. Wilson was writing about reverse T3 long before it was fashionable, and his position on it is more specific — and more cautious about the blood test — than most of what circulates. This guide collects the passages.

What reverse T3 is, in his summary

From the page comparing the syndrome with hypothyroidism:

• The Hypothalamus stimulates the Pituitary gland to produce Thyroid Stimulating Hormone (TSH).
• TSH stimulates the thyroid gland to produce T4 (thyroxine).
• T4 is the raw material used to make the active thyroid hormone T3.
• T4 is also converted to Reverse T3 (RT3) which is physiologically inactive.
• 80 percent of the active thyroid hormone T3 is produced outside the thyroid gland, in the tissues of the body.
• T4 is converted to T3 by an enzyme called 5′ Deiodinase.
• This enzyme is inhibited by stress, acute and chronic illness, fasting, cortisol (steroid), and other things.
• Under stress and fasting, the body converts less T4 to T3 and more T4 to RT3 to conserve energy (with less T3, the cells of the body slow down).

— Wilson’s Temperature Syndrome vs Hypothyroidism

The last line is the hinge. In his model, a stressed body shifts conversion away from active T3 toward inactive reverse T3, and the metabolism — and the temperature — slows.

The paper that started it

He has written about the moment the idea arrived:

Schimmel M: Thyroidal and Peripheral Production of Thyroid Hormones. Annals of Internal Medicine 87:760-768,1977.

The article explained that T4 is converted to either T3 (which is active) or RT3 (which is inactive) and that most of this conversion happened outside the thyroid gland. I started using more T3 and started getting better results in some of my patients.

Some of my patients weaned off the T3 when they went away for the summer and we found that they needed less T3 when they came back for the winter. Then I started cycling patients on and off T3 on purpose and found people needed less and less T3 until many times they could wean off completely. That’s how I knew that we were looking at a medical condition that hadn’t been previously described, Wilson’s Temperature Syndrome.

— Reverse T3, T3 & Body Temperature

He is careful about what he claims to have added:

To be clear, I didn’t invent T3. And Dr. Broda Barnes was the one that pointed out that low body temperatures can correlate better with low thyroid symptoms than thyroid blood tests. My contribution was finding that people with low temperatures and normal thyroid blood tests can often recover from one or more cycles of T3, and remain improved even after the treatment’s been discontinued.

— Reverse T3, T3 & Body Temperature

The vicious cycle he proposes

This is the mechanism the whole protocol rests on, and it is a hypothesis — his — not an established finding:

It appears that the increased levels of RT3 (see above) in the tissues that result from an impaired conversion of T4 to T3 can then further inhibit the conversion of T4 to T3 (by hogging the 5′-Deiodinase enzyme). This appears to result in a persistent impairment in the conversion of T4 to T3 in the tissues (with even more T4 being converted to RT3, less to T3, and so on) with the body getting stuck in a vicious cycle.

This could explain a reversible thyroid condition because clearing the RT3 levels out of the tissues (which can be accomplished with T3 medicine but not T4) could reset the system so that it could function normally on its own again. And because all this happens in the tissues and cells of the body it would be essentially out of the reach of, and therefore undiagnosable by, thyroid blood tests.

— Wilson’s Temperature Syndrome vs Hypothyroidism

The words “appears”, “could explain” and “could reset” are his, and they matter. The critics’ objection is precisely that this model is not established.

Why he does not rely on a reverse-T3 blood test

Here is where his view diverges from the popular one. A high rT3 result does not, for him, confirm the syndrome — and a normal one does not rule it out:

Patients can have normal TSH, and normal T4 levels and still respond well to the WT3 protocol. Not only that, but people can have normal results on the following tests: Total T3’s, Free T3’s, Total T4’s, and Reverse T3’s and still respond well to T3 therapy. In addition, even people with high T3’s and/or low RT3’s can also respond extremely well to the WT3 protocol.

Hearing about the importance of T4 to T3 conversion and RT3, some physicians and labs have started looking at Total T3, Free T3, Total T4, Free T4, Total RT3, and T3/RT3 ratios. But none of these tests demonstrate T4 to T3 conversion in the tissues and cells of the body. They only show what’s floating around in the blood stream just like any other blood test.

— Wilson’s Temperature Syndrome vs Hypothyroidism

The doctor’s manual gives the same idea as an image:

Likewise, when doctors make sure T4 levels look about right on the blood tests, that T4 may get converted to T3 (which is 4 times more active than T4), or it might get converted to RT3 which is totally inactive. How much goes one way or the other can change readily (on the order of days or perhaps even hours) depending on the circumstances. Managing patients while taking body temperature patterns into account is like holding the pencil down by the point.

— Limitations of Thyroid Blood Tests, the doctor’s manual

This is also written into the tenets every certified practitioner agrees to: diagnosis “based on low body temperature and symptoms – not on blood tests (including levels of T3 or RT3)” (the guidelines).

What he watches instead

The measurement, again, is the temperature pattern — its level and its steadiness — and the method is on How to Check Your Body Temperature for WTS. Whether clearing reverse T3 with cycles of T3 is what the protocol actually does is the open question; how the cycles are structured is collected in The WT3 Protocol, Explained.

Where to go from here

• Wilson’s Temperature Syndrome vs Hypothyroidism — the full page, with his diagram of the system.
• Reverse T3, T3 & Body Temperature — the article in his voice.
• Thyroid tests and diagnosis — everything on the site about TSH, T4, T3 and rT3.
• Order Your Own Lab Tests — if you want the numbers anyway; he explains what they can and cannot show.

This is a reader’s guide compiled from Dr. Wilson’s published writing; every quotation is his and links to its source. His model of reverse T3 is a hypothesis, described here as one. Nothing on this page is medical advice.