GLP-1 Peptides | Research Compounds for Metabolic Disease Studies

The GLP-1 receptor agonist class spans selective peptide agonists, dual receptor co-agonists, triple receptor co-agonists, and the first oral non-peptide agonist — each answering a distinct mechanistic research question. QSC supplies all compounds in this category in-house at ≥99% purity with domestic shipping to five regions.

Research Compounds in This Category

QSC supplies five GLP-1 receptor agonist research compounds, covering the full spectrum from selective GLP-1R agonism through triple receptor co-agonism and oral small-molecule activation:

Choosing the Right GLP-1R Agonist for Your Study

Each compound in this category activates GLP-1R but through different molecular mechanisms and with different co-receptor profiles. The choice of compound is a fundamental experimental design decision because it determines which receptor biology is active in your model.

• Semaglutide — the selective GLP-1R agonist reference standard. Use when you want to study pure GLP-1R pharmacology or replicate the clinical reference for CVOT mechanistic research.
• Tirzepatide — dual GLP-1R+GIPR. Use when the research question involves the additive GIP contribution to insulin secretion, adipose lipolysis, or weight reduction beyond selective GLP-1R agonism.
• Retatrutide — triple GLP-1R+GIPR+GCGR. Use when studying the GCGR contribution to thermogenesis, fat oxidation, and the maximum achievable weight reduction from receptor co-agonism. Comparing retatrutide with tirzepatide in parallel arms isolates the GCGR effect.
• Orforglipron — oral non-peptide allosteric GLP-1R agonist. Use for allosteric vs orthosteric binding pharmacology, oral GLP-1R delivery models, or biased agonism research.
• Liraglutide — foundational GLP-1R agonist with the longest published research history. Use as a historical reference standard or when LEADER CVOT comparability is required.

Research Guides

Frequently Asked Questions

What are GLP-1 receptor agonists?

GLP-1 receptor agonists are compounds that activate the glucagon-like peptide-1 receptor (GLP-1R), a class B GPCR expressed on pancreatic beta cells, the hypothalamus, heart, kidney, and GI tract. Activation stimulates glucose-dependent insulin secretion, suppresses glucagon, delays gastric emptying, and reduces appetite. GLP-1R agonists are the most clinically significant class in metabolic disease pharmacology, with approved drugs including semaglutide (Ozempic/Wegovy), tirzepatide (Mounjaro/Zepbound), and orforglipron (2025).

What is the difference between semaglutide, tirzepatide, and retatrutide?

Semaglutide is a selective GLP-1R agonist. Tirzepatide adds GIPR co-agonism (dual GLP-1R+GIPR). Retatrutide adds a third receptor — GCGR — producing triple co-agonism. Each additional receptor adds incremental weight reduction: semaglutide ~15%, tirzepatide ~22%, retatrutide ~24% in Phase 2/3 data. For research purposes, the three compounds in parallel experimental arms allow isolation of the GIP and glucagon receptor contributions to metabolic outcomes.

Which GLP-1 peptide should I use for my research?

Depends on your research question: semaglutide for the GLP-1R reference standard and CVOT mechanistic research; tirzepatide for dual GIP+GLP-1R biology or maximum metabolic effect in T2D models; retatrutide for triple receptor co-agonism and GCGR contribution studies; orforglipron for oral non-peptide GLP-1R agonism and allosteric pharmacology research. All four are supplied by QSC at ≥99% purity with Janoshik COA.

Does QSC supply all GLP-1 peptides with domestic shipping?

Yes. QSC ships semaglutide, tirzepatide, retatrutide, orforglipron, and liraglutide from domestic warehouses in the USA, EU, UK, Canada, and Australia — five regions with no international customs delays.