Eloralintide: Amylin Receptor Agonist Research Overview

Reference values identify the molecule. Always confirm identity and purity against the batch Certificate of Analysis.

Eloralintide is a synthetic peptide designed by its developer as a selective amylin receptor agonist. It belongs to the amylin-analog class of peptides: molecules modeled on the 37-residue pancreatic hormone amylin (also called islet amyloid polypeptide, IAPP) but engineered for chemical stability and an extended half-life in experimental systems.

Native human amylin is a difficult laboratory molecule. It carries a Cys2–Cys7 disulfide bridge and a C-terminal amide, and it readily self-associates into amyloid fibrils in solution. Amylin-analog programs such as the one that produced Eloralintide aim for peptides that keep receptor activity while resisting aggregation, which makes them far more practical for receptor pharmacology work.

Eloralintide carries a C20 fatty diacid side chain. This kind of lipidation lets a peptide bind reversibly to serum albumin, which slows its clearance in experimental systems; it is the same general strategy used in other long-acting incretin and amylin analogs.

Key identifiers:

• Name: Eloralintide
• Development code: LY3841136
• Class: amylin receptor agonist peptide (amylin analog)
• Molecular targets: amylin receptors (AMY1, AMY2, AMY3)
• CAS number: 2883634-40-8
• Developer: Eli Lilly and Company

To understand Eloralintide, it helps to understand the unusual architecture of its target. There is no single gene for an “amylin receptor.” Instead, amylin receptors are heteromeric complexes formed when the calcitonin receptor (CTR), a class B1 G protein-coupled receptor, pairs with one of three receptor activity-modifying proteins (RAMPs):

• AMY1 = CTR + RAMP1
• AMY2 = CTR + RAMP2
• AMY3 = CTR + RAMP3

RAMPs are single-pass transmembrane proteins that change the ligand-binding pocket, trafficking and signaling bias of the receptor they partner with. CTR expressed alone responds preferentially to calcitonin; CTR associated with a RAMP gains high affinity for amylin. The same RAMP family also pairs with the calcitonin receptor-like receptor (CLR) to form CGRP and adrenomedullin receptors, which is why amylin-pathway pharmacology is studied alongside the broader calcitonin/CGRP peptide family.

Upon agonist binding, amylin receptors couple predominantly to G_s, raising intracellular cAMP, and can also engage other G proteins, ERK1/2 phosphorylation and β-arrestin pathways. Comparing activity at CTR alone versus AMY1–3 is a central question in amylin-analog research, and “selectivity” in this context refers to that receptor-level comparison.

Eloralintide is used as a tool compound in amylin/calcitonin receptor pharmacology. Typical in vitro approaches include:

• cAMP accumulation assays (HTRF, luminescence or reporter-gene formats) in cell lines engineered to express CTR with or without RAMP1, RAMP2 or RAMP3
• Radioligand or fluorescent-ligand binding to estimate affinity at each receptor complex
• β-arrestin recruitment and receptor internalization assays to characterize signaling bias
• Phospho-ERK1/2 measurements to profile downstream kinase signaling
• Selectivity panels against related class B1 receptors such as CLR/RAMP complexes and the GLP-1 receptor

Because amylin-analog peptides vary in their preference for AMY receptors versus CTR alone, researchers often run concentration–response curves across the full receptor panel and compare potency (EC₅₀) and maximal response (E_max) side by side.

Lilly’s discovery paper (Briere et al., “Eloralintide (LY3841136), a novel amylin receptor agonist…: from discovery to clinical proof of concept,” Molecular Metabolism, 2025) describes eloralintide as a full agonist at human AMY1, AMY3 and the calcitonin receptor, with roughly an order of magnitude higher potency at AMY1 than at AMY3 or CTR alone. That AMY1 preference is what “selective” means in its description.

Eloralintide acts on a receptor system distinct from the incretin receptors. Peptides such as tirzepatide and retatrutide are agonists at the GLP-1 receptor, GIP receptor and, for retatrutide, the glucagon receptor. All of these are class B1 GPCRs, but amylin receptors differ in requiring a RAMP partner to form the high-affinity complex.

For receptor background on the incretin side, see the tirzepatide research overview and the retatrutide research overview.

Eloralintide is often listed next to GLP-1 compounds, and some suppliers shelve it in a “GLP” collection, but it is not a GLP-1 receptor agonist. It belongs to the amylin analog class, alongside these other investigational molecules:

The practical research difference is selectivity. Cagrilintide activates the calcitonin receptor alone about as well as the amylin receptors, while eloralintide was engineered to favor AMY1. Comparing the two across CTR and AMY1–3 cell lines is a direct way to study what each receptor contributes. Cagrilintide is also studied in combination with semaglutide, a pairing that is one reason amylin analogs are often grouped with GLP-1 compounds.

Eloralintide is an investigational molecule and is not an authorized product for any use. Eli Lilly and Company completed Phase 2 studies and in 2026 began a Phase 3 program named ENLIGHTEN. It includes several studies that evaluate eloralintide alone and alongside incretin agonists, registered on ClinicalTrials.gov (for example NCT07321886) and the EU Clinical Trials Information System.

Eloralintide is one of several amylin-pathway peptides in clinical development by different companies. Researchers following this field track registry entries at ClinicalTrials.gov and peer-reviewed publications on PubMed for the latest study designs.

Research-grade Eloralintide is supplied as a lyophilized peptide. Standard analytical documentation includes:

• Identity by mass spectrometry (ESI-MS or MALDI-TOF), confirming the observed mass against the expected molecular weight
• Purity by reversed-phase high-performance liquid chromatography (HPLC) with UV detection, reported as percent area of the main peak
• Endotoxin testing (LAL) where material is intended for cell-based assays
• Appearance and net peptide content, which matter for preparing accurate stock concentrations

A certificate of analysis (COA) should tie each of these values to a specific lot number. See also HPLC testing for peptides and endotoxin testing.

Like other amylin-family peptides, Eloralintide should be handled with attention to aggregation and adsorption. General laboratory practice for lyophilized peptides applies:

• Store the sealed vial at −20 °C or below, protected from light and moisture
• Allow the vial to reach room temperature before opening to limit condensation
• Prepare working solutions in buffers suited to the assay, aliquot them, and avoid repeated freeze–thaw
• Use low-binding plastics when working at low concentrations

More detail is available in peptide storage best practices.

NuRev supplies Eloralintide for laboratory research use only; it is not for human or veterinary use.