The Claim
Thyroxine (T4) is converted in peripheral tissues to triiodothyronine (T3) or reverse T3, and the ratio of T3 to reverse T3 determines metabolic activity.
What the research says
Supports is higher
Support is ahead, but a single strong opposing study can change this.
These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.
The body converts the thyroid hormone T4 into two different forms: T3, which increases metabolic rate, and reverse T3, which does not. The relative amounts of these two forms determine how active metabolism is.
See the scientific wording
Thyroxine (T4) is converted in peripheral tissues to either the active hormone triiodothyronine (T3) or the inactive reverse T3, and the balance between these forms determines metabolic activity.
The body converts the thyroid hormone T4 into two different forms in tissues like the liver and kidneys: one that activates metabolism (T3) and one that blocks it (reverse T3). The amount of each form produced depends on which enzyme acts on T4. When the enzyme that makes T3 is active, metabolism speeds up. When the enzyme that makes reverse T3 is active, metabolism slows down. The ratio between these two forms directly controls how fast or slow the body uses energy.
What the research says
3 studiesThe body turns the thyroid hormone T4 into two different forms: one that boosts metabolism (T3) and one that doesn’t (reverse T3). This study shows that about half or more of the T4 gets turned into the inactive form, proving that the balance between these two determines how active your metabolism is.
The study gave people a drug that changed how their body turns one thyroid hormone into two others — one that speeds up metabolism and one that doesn’t. When the active one went down and the inactive one went up, metabolism slowed, which supports the idea that the balance between these two forms controls how active your body is.
Study: Intra-amniotic injection of thyroxine (T4) to a human fetus
Scientists gave extra thyroid hormone to a developing baby and found that the baby’s body turned most of it into an inactive form (reverse T3), not the active one (T3). This supports the idea that the body chooses between making metabolism faster or slower by converting one hormone into two different versions.
Score breakdown, mechanism chain, raw evidence, ideal studies needed & 3 supporting studies
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.