GLP-1 (Native)

Glucagon-Like Peptide-1 (7-36 amide) — Endogenous Incretin

Evidence & Status

  • Strong Human Evidence
  • Established

At a Glance

The naturally produced incretin hormone that inspired the GLP-1 receptor agonist drug class. Direct human studies confirm its role in glucose-dependent insulin secretion and glucagon suppression; the cardiovascular and other outcome data associated with GLP-1 drugs belong to those separate drug entries.

Plain English

Researchers study native GLP-1 because it's the body's own hormone behind the GLP-1 receptor, the target of major metabolic drugs. Human studies confirm it's released after meals, boosts insulin in proportion to blood sugar, and slows the stomach's emptying. It breaks down within minutes in the bloodstream, which is why longer-acting drug versions were developed. The additional benefits reported for GLP-1 drugs (heart or kidney protection, weight-loss trial results) are findings about those specific drugs, not proof of what the natural hormone itself does when it isn't modified.

Overview

GLP-1 (7-36 amide) is the biologically active, C-terminally amidated form of glucagon-like peptide-1 (HAEGTFTSDVSSYLEGQAAKEFIAWLVKGR-NH2), an incretin hormone secreted postprandially by L-cells of the distal small intestine and colon. In direct human studies, native GLP-1 infusion stimulates glucose-dependent insulin secretion and suppresses glucagon (Kreymann et al., 1987), and — via the antagonist exendin(9-39) — a separate study found GLP-1's insulinotropic and glucagonostatic effects are preserved (unlike GIP's) in type 2 diabetes (Nauck et al., 2011). Another human study using the exendin(9-39) antagonist confirmed GLP-1's physiological role in postprandial glucose control (Edwards et al., 1999). The endogenous peptide's half-life of ~1–2 minutes, due to DPP-4 cleavage, is why pharmaceutical development focused on DPP-4-resistant analogs (semaglutide, liraglutide, exenatide, tirzepatide — all covered in their own entries). This entry describes native GLP-1 physiology only; the cardiovascular, renal, and other outcome trial data for GLP-1 receptor agonist drugs belong to those separate drug entries and are not carried here.

Research Summary

Native GLP-1(7-36)NH2's incretin physiology is established across direct human studies: infusion stimulates glucose-dependent insulin secretion and suppresses glucagon, and antagonist studies (exendin 9-39) confirm its physiological role in postprandial glucose control. Unlike GIP, native GLP-1's insulinotropic effect is preserved in type 2 diabetes. Its short (~1–2 minute) plasma half-life due to DPP-4 cleavage was the central pharmacological problem solved by DPP-4-resistant analogs. This entry is an educational reference for native GLP-1 physiology; the cardiovascular, renal, and long-term efficacy outcomes associated with GLP-1 receptor agonist drugs are documented in those drugs' own entries and are not evidence about the native hormone itself.

Research Areas

  • Insulin secretion
  • Appetite regulation
  • Gastric motility
  • Beta-cell preservation
  • Cardiovascular protection
  • Neuroprotection

Safety & Risks

Serious Risks

  • Not applicable as a standalone compound; see individual GLP-1 receptor agonist entries for therapeutic risk profiles

Reported Side Effects

  • At supraphysiologic levels: nausea, reduced gastric motility (basis for GLP-1 agonist side effects)
United States
Endogenous hormone — not itself an approved drug; GLP-1 receptor agonist drugs (semaglutide, liraglutide, exenatide, tirzepatide) are FDA-approved separately — see their own entries for regulatory status
United Kingdom
Not a licensed drug itself; see the relevant GLP-1 receptor agonist drug entries for regulatory status
Australia
Not a licensed drug itself; see the relevant GLP-1 receptor agonist drug entries for regulatory status
Canada
Not a drug itself; see the relevant GLP-1 receptor agonist drug entries for regulatory status

Citations & Sources