What is GLP-1? (Peptide Glossary)

GLP-1 (glucagon-like peptide-1) is a natural incretin hormone released by the intestine after eating. It stimulates glucose-dependent insulin secretion, suppresses glucagon, slows gastric emptying, and signals satiety to the brain. Native GLP-1 has a half-life of about two minutes - which is why the pharmaceutical industry spent decades engineering long-acting versions.

GLP-1 receptor agonists are the most commercially successful peptide class ever developed. Semaglutide (Ozempic/Wegovy), liraglutide (Victoza/Saxenda), and the dual GIP/GLP-1 agonist tirzepatide (Mounjaro/Zepbound) all derive from this pathway. Their published clinical trial programs documented substantial effects on weight and glycemia, driving the enormous search demand that now dominates the research peptide market.

In the RUO market, GLP-1-class peptides are simultaneously the highest-demand and highest-counterfeit-risk compounds. Their complex synthesis (long sequences with fatty acid modifications) has a real cost floor, so deep-discount GLP-1 peptides are a reliable red flag. Third-party mass spectrometry confirmation is essential for this category.