A complete pathway map of T4 and T3 metabolism and clearance

Biochemical pathway maps are an important aspect of medical education and medical problem-solving. They help us to view a network or series of chemical reactions in cells. In this article, I present a comprehensive science-based pathway map showing all the major pathways of both T4 and T3 hormone metabolism, also including their urinary clearance. I … Continue reading A complete pathway map of T4 and T3 metabolism and clearance

The leaky buckets analogy of thyroid hormone metabolism

Thyroid hormone metabolism is a very complicated system. A visual analogy sometimes goes a long way to assist comprehension. Throughout the body, there are at least six major pathways for T4 transformation or excretion, and at least six major pathways for T3 transformation or excretion. In the visual, the fluid represents circulating thyroid hormone concentrations. … Continue reading The leaky buckets analogy of thyroid hormone metabolism

An example of confusion about Free T3: Free T4 ratios

There's a lot of confusion out there about Free T3: Free T4 ratios in bloodstream. Part of the confusion is about how these ratios are expressed in numbers and phrases. Should you express this ratio in blood as 1:4, 4:1 or 0.25, or 4.00? A second confusion may lead to a more substantial and harmful … Continue reading An example of confusion about Free T3: Free T4 ratios