EP 172:42

Every organ a GLP-1 touches

Name: Every organ a GLP-1 touches
Uploaded: 2026-09-28
Duration: 2 min 42 s
Description: A tour of the body on real 3D anatomy: where GLP-1 receptors are found, what the drugs do in the pancreas, stomach, brain and gut, the liver, heart and kidney trial results and who they apply to, the gallbladder risk, and why the lungs are still an open question.

A tour of the body on real 3D anatomy: where GLP-1 receptors are found, what the drugs do in the pancreas, stomach, brain and gut, the liver, heart and kidney trial results and who they apply to, the gallbladder risk, and why the lungs are still an open question.

Transcript and sources

One weekly shot goes in under the skin. But the drug doesn't stay there. Its effects reach from your brain to your kidneys. Here's every stop.
Your own GLP-1 lasts about a minute or two. Semaglutide lasts about a week. Scientists have found GLP-1 receptors in the pancreas, gut, brain, heart, kidneys and lungs, in human and monkey tissue.
First stop, the pancreas. Here it boosts insulin, but only when blood sugar is high. As sugar falls back to normal, that push fades.
Next, the stomach. It empties more slowly, so you stay full longer. But that effect fades. In one trial, the delay shrank from about seventy minutes to about thirty over a few months.
Then the brain. GLP-1 receptors have been found in the human hypothalamus and brainstem, the brain's hunger and nausea centres. In a twenty-week trial, people on semaglutide ate about a third less at a free-choice lunch.
The gut is where many people feel it. In the big semaglutide weight trial, about forty-four in a hundred people had nausea, versus about seventeen on placebo.
The liver is the twist. It seems to have few or no GLP-1 receptors. Yet in a trial of people with a serious fatty-liver disease called MASH, the disease cleared on biopsy in about sixty-three percent on semaglutide, versus thirty-four percent on placebo. That's probably weight loss and better metabolism, not the drug acting on the liver directly.
Tucked under the liver is the gallbladder. Across seventy-six trials, gallbladder problems were about a third more common on GLP-1 drugs, though still uncommon overall.
The heart. In people with heart disease and excess weight but no diabetes, semaglutide cut heart attacks, strokes and heart deaths by about a fifth. It also nudges resting heart rate up by a few beats per minute.
The kidneys. In people with type 2 diabetes and kidney disease, semaglutide lowered the risk of serious kidney events by about a quarter. The heart, kidney and liver trials were funded by Novo Nordisk, which makes semaglutide.
And the lungs. The receptors are there, but the benefits are still early signals, mostly from health records.
One weekly shot, a whole-body map, and plenty still being mapped. Every study is at peplexicon.com.

Sources