GLP-1 (7–36) amide vs Glucagon-like peptide 2

How they're alike

GLP-1 (7–36) amide and glucagon-like peptide 2 are members of the proglucagon-derived peptide (PGDP) family — both are cleaved out of the same proglucagon precursor by tissue-specific prohormone processing, alongside glucagon, oxyntomodulin, glicentin, and glicentin-related pancreatic peptide (Lafferty 2021). In intestinal L-cells, the proglucagon precursor is cut by prohormone convertase 1/3 to liberate GLP-1, GLP-2, oxyntomodulin, and glicentin in parallel, so the two peptides share a common biosynthetic origin and a common cell of release (Lafferty 2021). The evolutionary conservation of the proglucagon gene itself is reflected in the early sequencing of the guinea pig preproglucagon gene, which showed that mutations in the prohormone are restricted to a specific portion of the precursor sequence rather than distributed uniformly across the GLP-1 and GLP-2 regions (Seino 1986). Both peptides are therefore products of one of the most studied prohormone-processing systems in mammalian endocrinology.

How they differ

The decisive difference between the two records is the depth of attached evidence. GLP-1 (7–36) amide is one of the most extensively characterised endogenous peptide hormones — it was identified as a physiological incretin in humans by Kreymann and colleagues, who showed that infusion potentiated glucose-induced insulin secretion at physiological concentrations (Kreymann 1987), and its receptor pharmacology, signalling, and place in the broader proglucagon-derived therapeutics field have been mapped in detail (Donnelly 2012, Graaf 2016). The Peptidopedia card for glucagon-like peptide 2, by contrast, is built from a single rat (Rattus norvegicus) sequence record originating from the early proglucagon gene work; no receptor assay, animal-model efficacy, or human-evidence data is attached to that card. Any cross-peptide claim about GLP-2 mechanism, indication, or pharmacology therefore has no in-dossier source on this comparison page.

The two peptides also differ structurally. The stored GLP-1 (7–36) amide sequence is 30 residues and carries a C-terminal amide that is not visible in the bare letter string but is implied by the "(7–36) amide" naming and confirmed in the reference literature (Donnelly 2012). The stored GLP-2 sequence is 35 residues, with no modifications recorded on the card. A BLOSUM62 local alignment of the two stored sequences gives 33.3% identity across a 30-residue alignable region — consistent with a shared proglucagon ancestry but with substantial sequence divergence in the residues that determine receptor selectivity. Functionally, GLP-1 binds GLP-1R, a class B G-protein-coupled receptor, through the canonical two-domain binding mode in which the C-terminal half of the peptide is captured by the receptor's large extracellular N-terminal domain and the N-terminal residues engage the transmembrane bundle (Donnelly 2012, Graaf 2016); activation couples primarily to Gαs and raises intracellular cAMP (Graaf 2016). The corresponding receptor for GLP-2 is not specified in any source attached to the GLP-2 card in this dossier and cannot be cited here.

Head-to-head clinical evidence

No head-to-head clinical trial directly comparing GLP-1 (7–36) amide and GLP-2 was identified in the dossier — no PubMed candidates surfaced for the pair, no Qdrant text chunks co-discussing the two peptides were retrieved, and the two cards share zero references in common. This reflects the asymmetry between the two records rather than a head-to-head literature that simply was not pulled: GLP-1 (7–36) amide is studied as the endogenous reference ligand for an entire therapeutic class (Graaf 2016), while the GLP-2 card here is a sequence-only catalog entry. Comparative evidence between the two peptides as endogenous hormones — for example, their parallel release kinetics from L-cells after a meal, or the relative contribution of each to post-prandial physiology — would need to be sourced from primary literature not currently attached to either card.

Indirect context is available for GLP-1 alone: Salehi and colleagues used the GLP-1R 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, establishing the meaningful contribution of endogenous GLP-1 even in diabetes (Salehi 2010). Seino and colleagues reviewed how GLP-1 and the second incretin GIP together account for up to ~60% of post-prandial insulin release in healthy people, framing the incretin system as a two-hormone axis (Seino 2010). Neither of those lines of evidence speaks to GLP-2.

Safety profile comparison

Neither card carries an attached safety profile that supports a comparative statement. GLP-1 (7–36) amide as the native peptide is not a marketed drug; it is used clinically as a research probe in short infusions and as the biological reference ligand against which engineered GLP-1R agonists are characterised (Graaf 2016), so its "safety profile" is the safety of brief experimental infusions rather than a regulatory adverse-event package. The GLP-2 card in this dossier has no attached human, animal, or in-vitro safety data. Any safety-profile statement comparing the two endogenous peptides at this stage would have to come from sources outside the current dossier and is therefore omitted.

Indication overview

GLP-1 (7–36) amide as the native endogenous peptide is not a marketed drug in any jurisdiction identified in the dossier — its therapeutic translation is via engineered GLP-1R agonists (exenatide, liraglutide, semaglutide, tirzepatide) that re-engineer the 30-residue endogenous hormone for stability and duration (Graaf 2016). The GLP-2 card in this dossier is a research-sequence record with no approved therapeutic indication identified in attached sources. Both peptides are therefore "endogenous reference" entries on Peptidopedia rather than approved-drug entries; the comparison sits at the level of biosynthetic origin and proglucagon-family biology, not at the level of clinical indications. For the clinically translated GLP-1 analogs that descend from GLP-1 (7–36) amide, see the related comparison pages linked above.