The Claim

A 14-day administration of 75 μg/day of triiodothyronine in healthy adult men is associated with a 1.7-fold increase in free T3 levels, a 13–15% increase in resting metabolic rate, and upregulation of 381 genes in skeletal muscle involved in protein turnover, mitochondrial energy metabolism, and transcriptional regulation.

Source: In vivo regulation of human skeletal muscle gene expression by thyroid hormone.

What the research says

Supports is higher

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

Supports
52score
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.

How it works
1 study reviewed
In plain English

In healthy adult men, taking 75 micrograms of triiodothyronine daily for 14 days results in a 1.7-fold increase in free T3 hormone levels, a 13–15% increase in resting metabolic rate, and increased activity of 381 genes in skeletal muscle related to protein breakdown, energy production, and gene regulation.

See the scientific wording

A 14-day administration of 75 μg/day of triiodothyronine in healthy adult men is associated with a 1.7-fold increase in free T3 levels and a 13–15% increase in resting metabolic rate, accompanied by upregulation of 381 genes in skeletal muscle involved in protein turnover, mitochondrial energy metabolism, and transcriptional regulation, suggesting a broad molecular signature underlying thyroid hormone's thermogenic and catabolic effects.

Why this might work

Thyroid hormone enters muscle cells and turns on hundreds of genes that build more energy-producing machines, break down proteins, and rewire how the cell responds to signals. This makes the muscle burn more fuel at rest, produce more heat, and lose mass over time.

Verified mechanismbased on 1 study

What the research says

1 study

  1. Study: In vivo regulation of human skeletal muscle gene expression by thyroid hormone.

    Scientists gave healthy men a synthetic thyroid hormone for two weeks and found that it turned on hundreds of genes in their muscles that help burn energy and break down protein — exactly what the claim says happened.

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

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