GLP-1: the body's own 'I've eaten' hormone (GLP-1 7, 36 amide)
A natural hormone released from the gut after a meal that tells the pancreas to release insulin and tells the brain you're full; the molecule that drugs like Ozempic were designed to mimic. Natural hormone, not a drug.
A researcher, an agent, or an algorithm wrote down the sequence and picked a target to hit.
An AI model like OpenFold3 or AlphaFold built a 3D structure and scored how well it fits the binding site.
A second contributor repeated the computation on their own hardware and the scores matched.
Named peptide fragment — synthesized for research; ClinicalTrials.gov trials registered for parent compound or class
Fork this card to add platform evidence →
Endogenous peptide fragment — receptor binding/activity established in published literature; CT.gov evidence
Fork this card to add platform evidence →
What this is
GLP-1 (7–36) amide is the body's own "I've eaten" hormone — a 30-residue peptide released into the bloodstream by L-cells in the small intestine after a meal, which tells the pancreas to release insulin and tells the brain that food has arrived (Donnelly 2012). It is the active, amidated form of glucagon-like peptide-1 cleaved out of the larger proglucagon precursor, and it accounts for roughly 80% of the circulating bioactive GLP-1, with GLP-1 (7–37) making up most of the remainder (Lafferty 2021). This is the endogenous incretin that pharmaceutical GLP-1 receptor agonists — semaglutide, liraglutide, exenatide — were engineered to mimic on a longer timescale. The peptide carries a C-terminal amide that is not visible in the bare letter sequence; that amidation, along with rapid degradation by DPP-4, is part of why native GLP-1 has a circulating half-life of only a few minutes and cannot itself be used as a daily drug (Donnelly 2012, Graaf 2016).
History
GLP-1 was identified as one of the proglucagon-derived peptides during the early 1980s sequencing of the proglucagon precursor, and the 7–36 amide form was recognized over the following years as the physiologically active incretin (Lafferty 2021). The landmark demonstration that it was a true human incretin came from Kreymann and colleagues, who infused GLP-1 (7–36) into humans and showed it potentiated insulin release at physiological glucose concentrations — establishing GLP-1 as a "physiological incretin in man" (Kreymann 1987, Lancet). That paper is the origin point for the entire GLP-1 therapeutic field; everything that followed — exenatide, liraglutide, semaglutide, tirzepatide — descends from the recognition that this gut peptide could be turned into a drug if its rapid in-vivo degradation could be solved (Graaf 2016).
What it does
After a meal, L-cells in the lower small intestine and colon sense nutrients in the lumen and release GLP-1 (7–36) amide into the bloodstream (Spreckley 2015). Once in circulation, it binds the GLP-1 receptor (GLP-1R), a class B G-protein-coupled receptor expressed on pancreatic β-cells, on cells in the gastrointestinal tract, and on neurons in appetite-regulating brain regions (Donnelly 2012, Graaf 2016). Through that receptor, GLP-1 has several coordinated effects that together lower post-meal blood glucose and reduce food intake:
- It potentiates glucose-dependent insulin secretion from pancreatic β-cells — meaning it amplifies insulin release when blood glucose is high but not when it is low, which is why GLP-1-based drugs carry a lower hypoglycaemia risk than sulphonylureas (Meloni 2013).
- It suppresses glucagon secretion from pancreatic α-cells (Donnelly 2012).
- It slows gastric emptying, blunting the post-meal glucose spike (Donnelly 2012).
- It promotes satiety via central appetite circuits, reducing food intake (Donnelly 2012, Farhadipour 2021).
In healthy people, endogenous GLP-1 together with the other major incretin, GIP, accounts for up to roughly 60% of post-prandial insulin release (Salehi 2010). Salehi and colleagues used a GLP-1 receptor antagonist (exendin-(9–39)) to block endogenous GLP-1 signalling in people with and without type 2 diabetes, and showed that this blockade reduced post-prandial insulin secretion in both groups — direct evidence that the endogenous peptide is doing meaningful work even in diabetes, not just the pharmacological analogs (Salehi 2010).
Mechanism
GLP-1 (7–36) amide is one of several bioactive peptides cleaved out of the proglucagon precursor by tissue-specific processing — proglucagon in intestinal L-cells is cut by prohormone convertase 1/3 to liberate GLP-1, GLP-2, oxyntomodulin, and glicentin, while pancreatic α-cells process the same precursor differently to release glucagon (Lafferty 2021). Two bioactive GLP-1 forms exist in plasma — GLP-1 (7–36) amide and GLP-1 (7–37) — and they are equipotent at the receptor, but the amidated 7–36 form dominates circulating levels (~80%) (Lafferty 2021).
The receptor (GLP-1R) is a class B (secretin-family) G-protein-coupled receptor with a large extracellular N-terminal domain that captures the C-terminal half of the peptide and a transmembrane bundle that engages the N-terminal residues of GLP-1 — the canonical two-domain binding mode of class B GPCRs (Donnelly 2012, Graaf 2016). Activation couples primarily to Gαs and raises intracellular cAMP, which in β-cells amplifies glucose-triggered insulin exocytosis (Seino 2010, Meloni 2013). The signalling is biased and ligand-dependent: Koole and colleagues showed that small-molecule allosteric ligands of GLP-1R differentially modulate the responses to endogenous and exogenous peptide ligands in a pathway-selective manner, which has implications for screening GLP-1R drugs against the right reference ligand (Koole 2010).
The peptide is 30 residues with a C-terminal amide rather than a free carboxylate; that amidation is implied by the "(7–36) amide" naming and is not visible in any one-letter sequence string (Donnelly 2012).
The reason this peptide is not itself a usable drug is its pharmacokinetics. Native GLP-1 (7–36) amide is cleaved between Ala8 and Glu9 by dipeptidyl peptidase-4 (DPP-4), abolishing receptor binding within minutes; the entire field of GLP-1-derived therapeutics is built around engineering analogs that resist DPP-4 cleavage and/or bind albumin to extend half-life from minutes to hours or days (Graaf 2016).
Evidence
- Human: Endogenous GLP-1 (7–36) was first shown to act as a physiological incretin in humans by Kreymann and colleagues, who infused it into healthy volunteers and demonstrated potentiation of glucose-induced insulin secretion (Kreymann 1987). Salehi and colleagues later used pharmacological blockade of GLP-1R with exendin-(9–39) to quantify the contribution of endogenous GLP-1 to post-prandial insulin secretion in people with and without type 2 diabetes, finding that endogenous GLP-1 contributes meaningfully in both groups (Salehi 2010).
- Animal: Mechanistic and metabolic effects of GLP-1 in rodent models underpin the modern review picture of GLP-1R pharmacology (Graaf 2016).
- In vitro: GLP-1 (7–36) amide serves as the standard reference agonist in GLP-1R signalling assays, including studies mapping allosteric modulation of the receptor (Koole 2010) and characterising glucose-dependent β-cell insulin release downstream of GLP-1R (Meloni 2013).
Native GLP-1 (7–36) amide is not itself a marketed drug. It is used clinically as a research probe (short infusions) and as the biological reference against which engineered GLP-1R agonists are characterised. The therapeutic field — semaglutide (/card/pep-00016), liraglutide (/card/pep-10868), exenatide (/card/pep-04439), tirzepatide — all derive from re-engineering this 30-residue endogenous hormone for stability and duration (Graaf 2016, Galindo 2026).
Known effects
- Glucose-dependent insulin secretion (incretin effect) — Established in humans since 1987 (Kreymann 1987). Quantitatively, endogenous incretins (GLP-1 + GIP combined) account for up to ~60% of post-prandial insulin release in healthy people (Salehi 2010).
- Glucagon suppression — Reduces α-cell glucagon output (Donnelly 2012).
- Slowed gastric emptying — Delays post-meal glucose appearance (Donnelly 2012).
- Satiety / reduced food intake — Central appetite effect via GLP-1R-expressing neurons (Donnelly 2012, Farhadipour 2021).
Regulatory status
- US / EU: GLP-1 (7–36) amide as the native peptide is not a marketed drug. It is used as a research probe and as the biological reference ligand for GLP-1R pharmacology. The marketed agents in this class are engineered analogs of GLP-1 (exenatide, liraglutide, semaglutide, tirzepatide) (Graaf 2016, Galindo 2026).
Related peptides
- Semaglutide (/card/pep-00016) — engineered GLP-1 analog with C18 fatty-diacid spacer at Lys26 for once-weekly dosing.
- Liraglutide (/card/pep-10868) — first-in-class daily GLP-1 analog with γ-Glu-C16 lipid tail.
- Exenatide (/card/pep-04439) — exendin-4-derived GLP-1R agonist (Heloderma venom-origin scaffold).
- GIP — the second incretin hormone; works in parallel with GLP-1 (Seino 2010).
- Glucagon — sibling proglucagon-derived peptide acting at the opposing GCGR receptor (Lafferty 2021).
Research directions for this peptide, selected from the current sources — hypotheses you can explore and model. None of it is proven yet; tap any one to see the full thinking.
Does the amide at the end of GLP-1 do more than protect the peptide from breaking down: could it actually change how the receptor works?
If this is true, it could explain why some diabetes drugs work better than others and help scientists design new medicines that copy the natural hormone more precisely, potentially with fewer side effects for patients.
Might the end of the GLP-1 peptide stick briefly to the fat layer of the cell surface, acting like a magnet that holds it near the receptor before it fully binds?
If true, drug designers could change how long GLP-1 drugs last in the body by adjusting how strongly their tail sticks to cell membranes, without changing how well they bind the receptor itself.
Might the body naturally chop GLP-1 into smaller pieces that reach the brain and protect nerve cells, even at doses too low to affect blood sugar?
If true, it could open a new way to treat brain diseases like Parkinson's using a natural byproduct of a hormone we already understand, possibly with fewer side effects than current high-dose GLP-1 drugs.
▸full evidence table2 metrics
| metric | value | tool |
|---|---|---|
| ipTM | 0.8827939629554749 | boltz-2 |
| ranking score | 0.7326928377151489 | boltz-2 |
▸structural qualityopenfold3
| metric | value | note |
|---|---|---|
| gpde | 1.215 | global PDE — lower = better |
| disorder | NaN | fraction disordered |
▸3-letter notation
▸recipeboltz-2 1.0
| parameter | value |
|---|---|
| model | boltz-2 1.0 |
| weights | — |
| hardware | nvidia_nim_api |
| mlx version | — |
| python | — |
| random seed | — |
| msa strategy | none |
| diffusion samples | 1 |
| runtime | — |
| predicted by | mlx@peptide |
| predicted at | 2026-04-24 |
▸citationbibtex
@peptide{pep10774,
sequence = {YAEGTFISDYSIAMDKIHQQDFVNWLLAQK},
target = {glp-1r},
author = {peptidemodel},
year = {2026},
status = {bioassayed}
}