GLP-3/CAG: Research Blend Profile

GLP-3/CAG is not a single molecule but a defined blend of two peptides drawn from the same research area. It pairs an incretin-family agonist with an amylin analog, two mechanisms that sit on independent receptor systems. This profile covers what each constituent is, why the two are combined, and what the multi-receptor literature studies. For where the parts sit in the wider class, see the metabolic peptides overview.

What is GLP-3/CAG?#

GLP-3/CAG is a multi-compound research formulation supplied as a 1:1 blend by mass: 5 mg of GLP-3 and 5 mg of CAG in a single 10 mg vial. GLP-3 is this catalog's designation for a peptide that acts as an agonist at three incretin-system receptors at once, while CAG is Cagrilintide, a long-acting analog of the hormone amylin. The reason the two travel together in one formulation is mechanistic: incretin agonism and amylin agonism run on separate receptor systems, so pairing them lets a single research preparation touch two independent signaling arms. Because a blend has no single structure or molecular identity, the compound is described here through its two constituents rather than one quoted mass or sequence.

What does the incretin constituent contribute?#

The GLP-3 half of the blend is a triple agonist: it engages the GLP-1, GIP, and glucagon receptors together. Each receptor sits on a different arm of glucose and energy-balance signaling, so a single peptide reaching all three is studied as combined incretin engagement rather than a single pathway. That multi-receptor design is the whole point of studying it, and it has its own dedicated write-up in the GLP-3 compound profile and, in more depth, the incretin triple agonism explainer. This is receptor pharmacology and preclinical work, not evidence of effects in people.

What does the amylin constituent contribute?#

The CAG half is Cagrilintide, a long-acting synthetic analog of amylin, a hormone co-secreted with insulin. It binds amylin and calcitonin receptor complexes rather than the incretin receptors, so it reaches a signaling system the GLP-3 constituent does not touch. A lipidation modification gives it stability in solution and a long circulating half-life, which is documented in its Cagrilintide compound profile. Pairing an amylin analog with an incretin agonist is a recurring theme in the literature precisely because the two receptor systems are independent, so the signals do not simply duplicate one another.

Why are the two studied as a blend?#

The research interest in GLP-3/CAG follows from the fact that its two constituents are mechanistically unrelated. GLP-3 acts on the incretin receptors; Cagrilintide acts on amylin and calcitonin receptors. Because those pathways run in parallel, comparative pharmacology studies examine incretin agonists and amylin analogs both on their own and in combination, treating the pairing as a way to probe how two receptor systems behave alongside each other in the same preparation. The blend is one of the more frequently referenced multi-receptor formulations in this corner of the signaling literature. As with each constituent on its own, this is in-vitro and preclinical research and does not speak to outcomes in humans.

Handling and storage#

GLP-3/CAG ships as a single lyophilized powder and is reconstituted before use. Because it holds two peptides in one vial, handling follows the standard catalog practice for the less robust component: the reconstitution primer covers solvent choice and gentle dissolution, and the cold-chain article covers how stability changes once the powder is in solution. Store the lyophilized material at -20°C protected from light, keep reconstituted solution at 2–8°C, and minimize freeze-thaw cycles.

Sources and further reading#

• Coskun et al., LY3437943 — a triple GLP-1/GIP/glucagon receptor agonist, Cell Metabolism 2022 (doi:10.1016/j.cmet.2022.03.001): foundational pharmacology of an incretin triple agonist of the kind the GLP-3 constituent represents, characterizing activity at all three receptors.
• Cagrilintide lowers body weight through brain amylin receptors AMY1R and AMY3R (PMC12270663): receptor-mechanism study of the amylin analog that makes up the CAG constituent, in animal models.
• Development of Cagrilintide, a Long-Acting Amylin Analogue, J Med Chem 2021 (PMID 34288673): medicinal-chemistry account of the CAG constituent and the modifications behind its long half-life.