RT3 inhibits T4-T3 conversion. How worried should we be?

[Post updated May 2, 2021] Many thyroid patients have acquired concerns about Reverse T3 (RT3) by reading Kent Holtorf's web pages. Likely even more have learned by reading Reverse T3 information on the Stop the Thyroid Madness (STTM) thyroid patients' website, which has been influenced by Holtorf, whom they cite. On the positive side, both … Continue reading RT3 inhibits T4-T3 conversion. How worried should we be?

Deiodinase Type 3, not RT3, plays the T3-blocking role

A lot of internet myths and misinformation surrounds Reverse T3 (RT3). Well-meaning people have attributed to the hormone a “T3-blocking” function. However, the enzyme deiodinase type 3 (D3) (NOT Vitamin D3, which is very different) is the main blocker of T3 hormone. Deiodinase type 3 (D3), regulated by the DIO3 gene, is the enzyme that … Continue reading Deiodinase Type 3, not RT3, plays the T3-blocking role

Visualizing thyroid hormone activity in cells: T3 and RT3 in context

I've recently been inspired by an visual of thyroid hormone cellular action published by Bianco and colleagues in September, 2019. This visual has taught me a new way of seeing these hormones' pathways of movement and activity in our bodies. I've read Bianco's article quite thoroughly in light of the image, and as a result … Continue reading Visualizing thyroid hormone activity in cells: T3 and RT3 in context

The basics of thyroid hormone action, transport and conversion

This comprehensive educational post collects the basics of thyroid hormone, transport and conversion. T3 action on nuclear receptors Every organ and tissue in your body must maintain a healthy level of T3 hormone activity to function properly. Bloodstream T3 supply and local T3 action powerfully influences how every organ operates, from our liver to our … Continue reading The basics of thyroid hormone action, transport and conversion

Do you have a Reverse T3 problem?

Across Canada, Reverse T3 testing is often offered for a fee -- patients usually pay for it. It has been this way for more than a few years now. As patients (and doctors), we need to know when we can save our money and avoid testing Reverse T3 by learning about its elevation indirectly. Here's … Continue reading Do you have a Reverse T3 problem?