GLP-1, GIP, and Glucagon Receptors: The Biology Behind Incretin Research Peptides

Much of today's metabolic peptide research comes down to three receptors: GLP-1, GIP, and glucagon. Understanding what each does makes the whole family of incretin research peptides easier to follow. This is a research-only overview.

The GLP-1 receptor

GLP-1 (glucagon-like peptide-1) is an incretin hormone involved in glucose and appetite signalling. It is the single most targeted receptor in this field, and semaglutide is the reference GLP-1 agonist.

The GIP receptor

GIP (glucose-dependent insulinotropic polypeptide) is a second incretin receptor. Engaging it alongside GLP-1 is what defines a dual agonist such as tirzepatide.

The glucagon receptor

Glucagon signalling relates to energy expenditure and glucose release. Adding the glucagon receptor to the other two is what makes retatrutide a triple agonist.

Why the combinations matter

Single, dual, and triple agonists are studied to understand what each additional receptor contributes. Our agonist guide walks through the progression, and the amylin analogue cagrilintide adds yet another pathway.

Handling and study

These peptides are reconstituted with bacteriostatic water using the GLP-1 reconstitution guide and the reconstitution calculator.

Quality and verification

Because these are engineered, acylated molecules, purity documentation is essential. Understanding how purity is verified helps you evaluate each Certificate of Analysis.

Research use only. This article is educational and is not medical, legal, or financial advice. The compounds discussed are not approved for human or veterinary use, consumption, or therapeutic application.