Individual thyroid ranges are far narrower than lab ranges

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 four 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 … Continue reading Individual thyroid ranges are far narrower than lab ranges

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

Pharmaceutical equivalency of levothyroxine (LT4), liothyronine (LT3) and desiccated thyroid

In thyroid therapy, how many micrograms of Cytomel (T3) are equivalent to how many micrograms of Synthroid (T4)? Pharmaceutical equivalency statements in the product monographs for Pfizer Canada's Cytomel and for ERFA Canada's "Thyroid" (desiccated thyroid extract, DTE, or natural desiccated thyroid, NDT) both claim that a 25 mcg dose of Liothyronine sodium (L-T3) is … Continue reading Pharmaceutical equivalency of levothyroxine (LT4), liothyronine (LT3) and desiccated thyroid

L-T3 and L-T4 Equivalency: Reference List

Part 1: Five historical voices say: "No, 25 mcg of L-T3 Liothyronine isn’t equivalent to 100 mcg L-T4" Part 2: Contemporary thyroid science: "L-T3 pharmaceutical equivalency, Part 2: New thyroid science" REFERENCES Pharmaceutical monographs Armour Thyroid web page: https://www.rxlist.com/armour-thyroid-drug.htm#description Erfa Thyroid monograph, page 8 https://pdf.hres.ca/dpd_pm/00034857.PDF Pfizer Cytomel monograph, page 12 https://www.pfizer.ca/sites/default/files/201710/Cytomel_PM.pdf Mylan Synthroid monograph, page … Continue reading L-T3 and L-T4 Equivalency: Reference List

A Dialogue with Utiger: T3-based thyroid therapy over-suppresses TSH

Robert Utiger, M.D. (1931-2008) is well known in endocrinology as the father of the TSH test. Despite his trust in the TSH test, in his publications he acknowledged that TSH behaved very unnaturally in response to T3 levels in blood while dosing T3 thyroid medication. What Utiger discovered in the 1970s and 1980s about the … Continue reading A Dialogue with Utiger: T3-based thyroid therapy over-suppresses TSH