Think twice about cancelling patient-pay Reverse T3 tests

At the end of January 2020, Alberta Precision Laboratories established a new policy of cancelling patient-pay Reverse T3 (RT3) tests on standard laboratory test orders.  One memo in circulation explains the justifications based on RT3 silence in the 2012 and 2014 thyroid clinical guidelines. The memo was issued by Dr. Hossein Sadrzadeh, Section Chief, Clinical … Continue reading Think twice about cancelling patient-pay Reverse T3 tests

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