Stop spreading the unscientific myth about the normal T4:T3 ratio!

Sigh. Just sigh. Even some of our best thyroid patient advocates can unknowingly share misinformation about thyroid therapy. Yesterday I was saddened to read that even Mary Shomon, whose thyroid articles on Verywell.com are usually to be trusted, is spreading the unscientific myth about "normal" thyroid secretion ratios being 13:1 to 16:1. These statements are …

Continue reading Stop spreading the unscientific myth about the normal T4:T3 ratio!

LifeLabs BC handout reveals thyroid testing policy failure

This week, a thyroid patient from British Columbia posted an image of a piece of paper handed to her at a LifeLabs laboratory. LifeLabs BC was using this paper leaflet to explain to her why "Free T3 and Free T4 will not be tested when the TSH is in reference range." THE LEAFLET GIVEN TO …

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The loss of thyroid clinical knowledge from Werner & Ingbar’s The Thyroid

Decades ago, a lot more doctors knew how thyroid hormone levels influenced all organs and tissues’ health. It wasn’t all about the influence of thyroid hormones on the TSH. It was more about the influence of truly adequate thyroid hormone levels on real health outcomes. A lot more doctors learned and understood that if thyroid …

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Individual thyroid ranges are 38-68% the size of the lab reference range

We've known since at least 2002 that being within "normal range" is never good enough when it comes to thyroid hormone blood tests. An important set of articles has taught us that each human being has an optimal range for TSH, Total T4 and Total T3 that is far less the width of the population-wide …

Continue reading Individual thyroid ranges are 38-68% the size of the lab reference range

L-T3 pharmaceutical equivalency, Part 2: New thyroid science

What does NEW thyroid science have to say on the topic of thyroid pharmaceutical equivalency? How many micrograms of L-T3 Liothyronine (i.e. Cytomel) are equivalent to L-T4 Levothyroxine (i.e. Synthroid)? Thyroid hormone pharmaceutical monographs currently provide very rigid and low-ratio equivalency statements: ERFA Canada says "Desiccated thyroid 60 mg is usually considered equivalent to ... …

Continue reading L-T3 pharmaceutical equivalency, Part 2: New thyroid science

No, 25 mcg of L-T3 Liothyronine isn’t equivalent to 100 mcg L-T4

In thyroid therapy, how many micrograms of Cytomel (T3) are equivalent to how many micrograms of Synthroid (T4)? Equivalency statements in the product monographs for Pfizer Canada's Cytomel and for ERFA Canada's "Thyroid" (NDT brand) claim that a 25 mcg dose of Liothyronine sodium (L-T3) is "considered equivalent" to 100 mcg / μg (0.1 mg) …

Continue reading No, 25 mcg of L-T3 Liothyronine isn’t equivalent to 100 mcg L-T4