The Claim

Reverse-T3 constitutes approximately 62% of total triiodothyronine in hypothyroid patients and 57% in healthy controls.

Source: Extrathyroidal conversion of thyroxine to 3,3',5'-triiodothyronine (reverse-T3) and to 3,5,3'-triiodothyronine (T3) in humans.

What the research says

Supports is higher

Support is ahead, but a single strong opposing study can change this.

Supports
44score
Challenges
0score

These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.

Quantitative
1 study reviewed
In plain English

In both people with hypothyroidism and healthy individuals, reverse-T3 makes up about 62% and 57% respectively of the total amount of triiodothyronine in the blood.

See the scientific wording

Reverse-T3 accounts for approximately 62% of total triiodothyronine in hypothyroid patients and 57% in healthy controls, indicating that reverse-T3 is a quantitatively dominant metabolite of thyroxine in both groups.

Why this might work

The main thyroid hormone, thyroxine, is broken down in tissues like the liver and muscles by enzymes that remove iodine atoms. When iodine is removed from the inner ring of thyroxine, it becomes reverse-T3; when removed from the outer ring, it becomes T3. In both healthy people and those with underactive thyroids, the enzyme activity favors removal from the inner ring, making reverse-T3 the most common form produced. This process happens outside the thyroid gland and accounts for the majority of all triiodothyronine molecules in the blood.

Verified mechanismbased on 1 study

What the research says

1 study
  1. Study: Extrathyroidal conversion of thyroxine to 3,3',5'-triiodothyronine (reverse-T3) and to 3,5,3'-triiodothyronine (T3) in humans.

    In both healthy people and those taking thyroid medicine, most of the active thyroid hormone byproduct in the blood is reverse-T3 — more than half — meaning it’s the most common form made from the main thyroid hormone.

Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies

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Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.