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Why Reverse T3 Can Tell You More Than TSH (Part 2 of 3)

Kent Holtorf
Kent Holtorf

Medical Director, Holtorf Medical Group

8 hours ago
  • T4 needs more energy to enter the cell than T3. Each thyroid hormone has its own transporter, and the one for T4 is the most energy-dependent. When mitochondrial function drops, T4 uptake falls off first, which is my main reason for preferring T3 in patients with chronic illness.
  • A high reverse T3 points to poor transport. Reverse T3 behaves much like T4 at the cell membrane, so when it runs high in the blood, I read that as T4 struggling to get into the cells too. I pair it with the free T3-to-reverse T3 ratio and, in women, sex hormone-binding globulin.
  • Peptides and bioregulators work on a different timescale from hormones. Hormones act through receptors in the nucleus and are slow on, slow off. Most peptides act at the cell surface through secondary messengers, and bioregulators are chains of two to four amino acids with tissue-specific effects, studied mostly in Russia and still early by US standards.

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