Updated February 4, 2022

T4 is converted to T3 or RT3 by removal of an iodine from one of two different locations.  The ratio of conversion to T3 vs RT3 is influenced by several other factors, including cortisol/stress level,  levels of other hormones, and other signalling from the biome.  Bile acids are molecules made by the liver and contained in the bile. They not only help with fat processing, they act as hormones and have a direct effect on thryoid conversion.  (For more information on bile acids, click here.)

For videos demonstrating the conversions, see the menu at the top