Hormone Health Hub: Expert Insights on Testing, Balance & Better Living — thyroid and optimal wellness

Many patients produce sufficient thyroid hormone yet still suffer from classic hypothyroid symptoms. Why? Because standard TSH testing misses the full picture. In this clinical guide, Jim Paoletti explains the functional approach to thyroid assessment — examining T4 production, TBG binding, T4-to-T3 conversion, cortisol interference, ferritin and vitamin D — and outlines exactly which tests are needed for a complete analysis.

At 24, Dr. Kate Placzek was sleeping 16 hours a day and barely functioning — yet her standard blood tests came back normal. It took a TSH result in the mid-thirties to finally explain her debilitating fatigue. In this candid personal account, she shares her thyroid diagnosis, what she learned about optimal TSH levels, and why testing beyond TSH alone can make all the difference.

Reverse T3 (rT3) is one of the most misunderstood markers in thyroid testing. Often called the “hibernation hormone,” it is frequently claimed — without scientific basis — to block thyroid receptors and slow metabolism. In Part 2 of this series, Margaret Groves of ZRT Laboratory examines what the peer-reviewed literature actually says about rT3, when elevated levels are clinically meaningful, and how to interpret the T3/rT3 ratio in the context of a comprehensive thyroid assessment.

Thyroid symptoms can persist even when thyroxine (T4) levels appear normal — because thyroid function is profoundly affected by anything that disrupts the conversion of T4 to the active hormone T3 at the cellular level. In Part 1 of this two-part series, Margaret Groves of ZRT Laboratory explains the three deiodinase enzymes (D1, D2 and D3) that act as gatekeepers to intracellular thyroid hormone bioavailability, what affects circulating levels of T3 and reverse T3, and why selenium, iodine and inflammatory conditions all play a critical role.

Environmental pollutants are in the food we eat, the air we breathe and the water we drink — and in excess, they can profoundly disrupt thyroid hormone synthesis and action. This article explains how iodine and selenium deficiencies develop, how antagonists like bromine, arsenic and mercury exacerbate thyroid dysfunction, and why urine testing for these five elements can reveal the hidden environmental drivers of thyroid symptoms that standard blood tests miss.