Glucagon-like peptide-1 (GLP-1)
Also known as: GLP-1, glucagon-like peptide 1, GLP-1 (7-36) amide
Overview
Glucagon-like peptide-1 (GLP-1) is an endogenous incretin peptide hormone released from enteroendocrine L-cells, best known for amplifying glucose-stimulated insulin secretion after meals. In normal physiology, GLP-1 acts as a rapid, short-lived signal that links nutrient intake to pancreatic islet function, gastrointestinal motility, and appetite regulation. The native peptide is quickly degraded in circulation by dipeptidyl peptidase-4 (DPP-4), which is why therapeutic GLP-1 receptor agonists (e.g., semaglutide) are engineered for prolonged activity. On PeptideKnow, GLP-1 matters for two reasons. First, it is the biological template for modern obesity and type 2 diabetes drugs. Second, the popularity of GLP-1 receptor agonists has created a complex supply chain for peptide (and peptide-like) active ingredients, including bulk drug substances that are sometimes diverted into unapproved or counterfeit channels. When regulators refer to “GLP-1 receptor agonist bulk drug substances,” they are talking about the upstream materials used to manufacture finished products or compounded preparations—not a consumer product you should ever handle directly.
Mechanism of Action
GLP-1 binds the GLP-1 receptor (GLP-1R), a class B1 G-protein–coupled receptor that primarily signals through Gαs to increase intracellular cAMP. In pancreatic β-cells, this signaling potentiates glucose-dependent insulin secretion; GLP-1 also suppresses glucagon release, slows gastric emptying, and reduces appetite via central and peripheral pathways.
Potential Benefits
- Physiologic incretin signal that enhances glucose-stimulated insulin secretion
- Supports postprandial glucose control via insulin/glucagon modulation
- Contributes to appetite and gastric motility regulation
Research Dosage Notes
The following reflects doses used in published research studies. This is not medical advice.
Native GLP-1 is not typically used as a compounded or consumer peptide because it is rapidly degraded and because clinically used GLP-1 pathway medicines are regulated drug products. If you see ‘GLP-1’ sold as a consumer peptide or as bulk powder, treat it as a high-risk signal that the product is not part of a legitimate supply chain.
Routes of Administration
Not used as a consumer-administered peptide; therapeutic use is via GLP-1 receptor agonist drugs.
Read our full Routes of Administration Guide for detailed comparison of all delivery methods.
Amino Acid Sequence
Not listed here (multiple endogenous processed forms exist; the pharmacology of GLP-1 signaling is typically discussed via receptor agonists).
Side Effects & Safety
- Physiologic GLP-1 signaling can slow gastric emptying; drug-induced GLP-1R activation commonly causes nausea and GI symptoms, but those effects depend on specific agonists and dosing.
Safety & Contraindications
This information is for educational purposes only. Consult a qualified healthcare provider before using any peptide.
Native GLP-1 is not a consumer therapeutic
Personal or family history of medullary thyroid carcinoma or MEN 2
Pregnancy and lactation
Drug Interactions
- Oral medications (general):
- Insulin and sulfonylureas:
- Unapproved 'GLP-1' bulk powders:
Pharmacokinetics
| Half-Life | Very short; rapidly inactivated by DPP-4 (minutes-scale in circulation). |
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Synergistic Compounds
The following compounds have been studied alongside Glucagon-like peptide-1 (GLP-1) for potential complementary or synergistic effects:
Learn More
References & Further Reading
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