Search "GLP-2" and you might expect a newer, stronger version of GLP-1. It is not. GLP-2 is a related hormone, cut from the same precursor protein in the same cells of the gut, with a job that has almost nothing to do with appetite. Its one approved drug form treats people who have lost most of their small intestine.
This page sets the two side by side, from the protein record and the FDA label, as of 25 September 2026. What GLP-1 itself is and does is on our pages what is a GLP-1 and how GLP-1 works.
One precursor, three hormones
Human proglucagon is a 180-amino-acid protein. Different cells cut it in different places. The pancreas makes glucagon from it; the intestinal L-cells make GLP-1 and GLP-2 from it. The positions, from UniProt's reviewed record (P01275):
| Piece | Positions in proglucagon | Length of the active form |
|---|---|---|
| Glucagon | 53–81 | 29 |
| GLP-1 | 92–128 (active form 98–128) | 31 |
| GLP-2 | 146–178 | 33 |
How alike are they? Laid side by side from the first residue, active GLP-1 and GLP-2 carry the same amino acid at 11 of 31 positions; GLP-1 and glucagon match at 14 of 29 (our count, a simple position-by-position alignment without gaps). By that measure GLP-1 is closer to glucagon than to its own "number 2". The glucagon relationship is on the Peptide Lexicon's glucagon entry.
Opposite jobs
| GLP-1 | GLP-2 | |
|---|---|---|
| Made in | intestinal L-cells, from proglucagon | the same L-cells, from the same proglucagon |
| Main actions | raises insulin when glucose is high, lowers glucagon, slows stomach emptying, reduces appetite | increases intestinal and portal blood flow, reduces stomach acid, makes the intestinal lining grow |
| Approved drugs | semaglutide, tirzepatide, liraglutide, dulaglutide, exenatide, orforglipron | teduglutide only |
| What the drugs treat | type 2 diabetes, weight, heart and kidney risk, sleep apnoea, liver disease | short bowel syndrome |
The GLP-2 actions in that table are the Gattex label's own description: GLP-2 "is known to increase intestinal and portal blood flow and inhibit gastric acid secretion", and teduglutide binds GLP-2 receptors in the gut wall. The GLP-1 column is set out, use by use, on our GLP-1 benefits page.
Put simply: GLP-1 drugs are used to help people eat less. GLP-2's drug is used to help a shortened gut absorb more.
The one GLP-2 drug: teduglutide
Gattex (teduglutide, Takeda, NDA 203441) is a 33-amino-acid GLP-2 analogue. Against human GLP-2 it differs at a single position — alanine replaced by glycine at position 2 (our comparison of the label's sequence with UniProt's). Its indication is short bowel syndrome in adults and children aged one and over who depend on parenteral (intravenous) support.
In its placebo-controlled trial (86 adults, 24 weeks), 63% on teduglutide against 30% on placebo reduced their weekly intravenous nutrition volume by at least 20% at both weeks 20 and 24. The average weekly reduction at week 24 was 4.4 litres on teduglutide against 2.3 litres on placebo, from starting volumes around 13 litres.
The growth effect is also the main warning. Because GLP-2 makes intestinal tissue grow, the label warns of "acceleration of neoplastic growth", and requires adults to have a colonoscopy and upper endoscopy with removal of any polyps within six months before starting, another after one year, and further ones at least every five years. If an intestinal cancer is found, treatment stops. No GLP-1 label carries a requirement of that kind; theirs is a thyroid warning, covered on our GLP-1 and cancer page.
Why the names mislead
"GLP" stands for glucagon-like peptide, and the numbers follow the order of the two pieces along the proglucagon chain — GLP-1 first, GLP-2 after it — not a progression. GLP-2 is not a second-generation GLP-1, and a GLP-2 drug is not a weight-loss drug. The weight-loss class is the GLP-1 receptor agonists — listed in full on our register of GLP-1 drugs.
What this page cannot tell you
- Whether GLP-2 drugs suit anyone. Short bowel syndrome is managed by specialist gastroenterology teams.
- How experimental GLP-2 drugs perform. This page covers the one US approval only.
Sources
- UniProt, entry P01275 (GCG_HUMAN, pro-glucagon), feature table and canonical sequence — rest.uniprot.org/uniprotkb/P01275, retrieved 25 September 2026. Residue comparisons are our own.
- GATTEX (teduglutide) prescribing information, Takeda, NDA 203441, effective 2025-09-05 — DailyMed: sections 1, 2, 5, 11, 12.1 and 14.1.
- MOUNJARO (tirzepatide) prescribing information, Eli Lilly, effective 2026-08-27 — DailyMed, section 12.1, for the incretin actions compared here.