EP 031:31

“GLP-2” and “GLP-3”, decoded

Name: “GLP-2” and “GLP-3”, decoded
Uploaded: 2026-09-28
Duration: 1 min 31 s
Description: There is no hormone called GLP-3. The nicknames count how many body signals a medicine copies.

There is no hormone called GLP-3. The nicknames count how many body signals a medicine copies.

Transcript and sources

There's no hormone called GLP-3. So what is everyone talking about?
Those names are counting something real: the body signals a medicine copies. Learn to count them, and the whole family makes sense.
Start with the real one. GLP-1 is a hormone your gut sends after a meal. It helps release insulin when blood sugar is high, and tells your brain you've had enough.
Most of these medicines copy only GLP-1: semaglutide, in Ozempic and Wegovy; liraglutide; dulaglutide; and a new pill, orforglipron.
Tirzepatide, in Mounjaro and Zepbound, copies two signals: GLP-1 and GIP. Online, that earns it the nickname GLP-2. But the real GLP-2 is a different hormone, one that helps the gut lining grow.
Retatrutide copies three: GLP-1, GIP, and glucagon. That's the GLP-3. Its maker calls the name inaccurate, and it's still in trials, not approved.
So skip the numbers and count the signals: GLP-1 alone, plus GIP, plus glucagon, or plus amylin, a fullness signal from the pancreas.
And if someone sells a GLP-3 labelled for research, it is not approved medicine. The FDA has sent warning letters to sellers using these names.
Every medicine, and the evidence behind it, is at peplexicon.com.

Sources