Cagrilintide (5mg)

Cagrilintide is a synthetic long-acting analogue of amylin, the pancreatic hormone co-secreted with insulin from pancreatic beta cells in response to a meal. It acts as a non-selective agonist at the three amylin receptor phenotypes AMY1R, AMY2R, and AMY3R, as well as at the calcitonin receptor.

The amylin receptors are not distinct genes; instead, each consists of the calcitonin receptor, a class B G protein-coupled receptor, paired with one of three receptor activity-modifying proteins (RAMP1, RAMP2, or RAMP3). This shared architecture explains why a single peptide can engage both the amylin receptor complex and the broader calcitonin receptor family.

Researchers can buy cagrilintide 5mg in Europe from Crystal Peptides. This is a high-purity research peptide independently tested by accredited laboratories for peptide identity, purity, and analytical consistency. Plus, every batch is accompanied by a Certificate of Analysis that can be traced directly to the independent testing laboratory for consistency in amylin receptor and metabolic research.

Cagrintide structural modifications

The molecule is built on the human amylin backbone with six targeted amino acid substitutions together with a lipid conjugation that extends its circulating half-life. Each modification contributes to the peptide's stability, receptor activity, or pharmacokinetic profile:

• Pro25, Pro28, and Pro29 are substituted from rat amylin to reduce β-sheet propensity, suppress amyloid fibril formation, and improve peptide stability during formulation.
• Glu14 and Arg17 are introduced to stabilise the central α-helix through the formation of a salt bridge.
• The disulfide bridge between Cys2 and Cys7 is retained from native amylin, preserving an important structural feature of the peptide.
• The C-terminus is amidated, improving resistance to enzymatic degradation.
• Pro37 replaces the tyrosine found in both human amylin and pramlintide, a modification borrowed from calcitonin to increase potency at the calcitonin receptor. Kruse et al. describe this substitution explicitly in the original development paper, and the registered molecular formula reconstructs only with proline at this position. Several vendor and reference pages incorrectly describe the substitution as P37Y, when the actual modification is Tyr37 → Pro37.
• A C20 fatty diacid is attached to the lysine side chain at position 1 through a γ-glutamate linker, promoting reversible albumin binding and extending the elimination half-life to approximately 159–195 hours, compared with 20–45 minutes for pramlintide. This prolonged half-life enables once-weekly investigation and is the principal reason cagrilintide exists as a distinct long-acting analogue.

Cagrilintide vs. incretin-based compounds

What separates cagrilintide from the compounds with which it is most often grouped is that it is not an incretin peptide. Semaglutide, tirzepatide, and retatrutide exert their biological effects through the GLP-1, GIP, and glucagon receptor systems. Cagrilintide instead acts through the amylin receptor pathway, influencing satiety signalling within regions of the brain such as the area postrema and hypothalamus. Because these pathways are complementary rather than overlapping, their biological effects are considered additive rather than competitive, providing the scientific rationale for investigating cagrilintide in combination with semaglutide as CagriSema.

Chemical properties and registry information

Clinical data

Cagrilintide has been studied both on its own and as the amylin component of CagriSema, the fixed combination with semaglutide 2.4mg. The distinction matters, because the figures most often attached to cagrilintide belong to the combination.

• Phase 2 dose-finding (Lau et al., The Lancet, 2021): 706 adults, 26 weeks. Cagrilintide 4.5mg produced 10.8% mean body-weight reduction against 3.0% on placebo and 9.0% on liraglutide 3.0mg, with a clear dose-response across the 0.3mg to 4.5mg range.
• Phase 1b combination (Enebo et al., The Lancet, 2021): cagrilintide co-administered with semaglutide 2.4mg reached 17.1% at 20 weeks.
• Phase 2 in type 2 diabetes (Frias et al., The Lancet, 2023): 92 adults, 32 weeks. CagriSema 15.6% against 8.1% for cagrilintide alone and 5.1% for semaglutide alone.
• REDEFINE 1 (Phase 3, NEJM 2025): 3,417 adults with obesity and no type 2 diabetes, randomised 21:3:3:7 to CagriSema (n=2,108), cagrilintide 2.4mg alone (n=302), semaglutide 2.4mg alone (n=302) or placebo (n=705) for 68 weeks. On the trial product estimand, CagriSema 22.7%, cagrilintide 11.8%, semaglutide 16.1%, placebo 2.3%. On the treatment policy estimand, 20.4%, 11.5%, 14.9% and 3.0% respectively.
• REDEFINE 2 (Phase 3, NEJM 2025): 1,206 adults with type 2 diabetes. CagriSema 15.7% on the trial product estimand, 13.7% on the treatment policy estimand, against 3.1% and 3.4% on placebo.
• REDEFINE 4 (Phase 3, reported February 2026): head to head against tirzepatide 15mg over 84 weeks. CagriSema 23.0% against 25.5% for tirzepatide. The trial did not meet its non-inferiority endpoint.

REDEFINE 1 is the only Phase 3 trial that has ever isolated cagrilintide as a monotherapy against an active comparator, and it is the number that should be quoted for this compound: 11.8% at 68 weeks. In the same trial, under identical conditions, semaglutide alone reached 16.1%. Cagrilintide alone was the weaker of the two components. The gap widens at the top end: 40.4% of the CagriSema arm lost 25% or more of body weight, against 16.2% on semaglutide alone and 6.0% on cagrilintide alone.

The dose-escalation data points the same way. At 68 weeks, 82.5% of the cagrilintide arm was on the highest dose, against 70.2% on semaglutide and 57.3% on CagriSema. Participants tolerated cagrilintide well enough to stay at the top dose more often than either comparator and still lost less weight, which places the ceiling on cagrilintide monotherapy at efficacy rather than tolerability. The value of the compound in the published research base is combinatorial: it adds roughly six to seven percentage points on top of semaglutide, through a receptor system semaglutide does not touch.

Gastrointestinal effects, principally nausea, are the dominant reported observation and are largely escalation-related. In the Phase 2 trial, 41% to 63% of cagrilintide participants reported gastrointestinal adverse events against 32% on placebo, with nausea at 20% to 47% against 18%. Long-term safety data remains under study.

Research applications

Cagrilintide is used as a molecular tool for investigating amylin signalling and the satiety pathways that operate independently of the incretin system. Because it engages the calcitonin receptor alongside all three amylin receptor phenotypes, it allows researchers to examine how RAMP composition shapes receptor pharmacology within a single receptor family.

Amylin and calcitonin receptor pharmacology

Cagrilintide is close to equipotent at AMY3R and the calcitonin receptor, and this non-selectivity is the point of the molecule rather than a shortcoming of it. Selective calcitonin receptor agonism alone does not control body weight in experimental models, while both selective amylin receptor agonists and non-selective agonists do. Cagrilintide sits at one end of that axis and gives researchers a reference compound for comparative work against selective analogues such as eloralintide, and against native amylin, salmon calcitonin and pramlintide.

Receptor residence time and signalling kinetics

Fletcher et al. characterised cagrilintide across 25 pharmacological endpoints and reported transient receptor binding on the order of minutes, closer to human calcitonin than to salmon calcitonin or the long-residence analogue AM1784. Residence time is an active research variable in this receptor family, and cagrilintide is a standard tool compound for examining how binding kinetics translate into downstream signalling.

Amyloid fibril formation and peptide stability

Human amylin is one of the most aggregation-prone peptide hormones known, and islet amyloid deposition is a feature of type 2 diabetes pathology. Cagrilintide carries the rat-derived proline substitutions that break beta-sheet formation, which makes it useful in comparative studies of fibrillation kinetics, nucleation and the sequence determinants of amyloid propensity.

Combination signalling with incretin pathways

The amylin and GLP-1 receptor systems are anatomically and mechanistically separate. Cell and animal models use cagrilintide alongside GLP-1 receptor agonists to examine how two non-overlapping satiety pathways interact, whether the interaction is additive or synergistic, and where the signals converge in hindbrain and hypothalamic circuits.

Gastric emptying and postprandial glucose handling

Amylin slows gastric emptying and suppresses postprandial glucagon release. Cagrilintide is used to probe those effects on a weekly rather than a per-meal timescale, which separates tonic amylin receptor activation from the meal-linked pulses produced by short-acting analogues.

How Cagrilintide works (mechanism of action)

Cagrilintide is a non-selective agonist of the calcitonin receptor family: the calcitonin receptor itself, and the three amylin receptor phenotypes formed when it dimerises with RAMP1, RAMP2 or RAMP3.

Target engagement

The calcitonin receptor is expressed at the cell surface both alone and in complex with RAMPs. Unaccompanied, it responds potently to calcitonin peptides and weakly to amylin. Paired with a RAMP, its pharmacology switches: high affinity for amylin, weak response to human calcitonin. Cagrilintide is potent at both phenotypes, which is what the calcitonin-derived C-terminal proline was engineered to achieve. The C20 fatty diacid on Lys1 binds albumin reversibly and holds the peptide in circulation.

Downstream signalling pathways

Like other class B1 GPCRs, the receptor family couples canonically to Gs, activating adenylate cyclase and raising intracellular cyclic AMP, with intracellular calcium mobilisation and ERK phosphorylation as further measured endpoints. RAMP composition modulates the profile rather than switching it, so the same agonist produces different response signatures depending on which RAMP is present. That is the property that makes this family a standing subject in signalling-bias research.

Cellular effects in experimental models

In preclinical models, cagrilintide reduces food intake in a dose-dependent manner and produces sustained reductions in body weight on once-weekly administration. The signalling site is the area postrema and hypothalamus rather than the periphery, and the pathway is independent of GLP-1 receptor activation, which is why the two produce additive effects when combined.

Cagrilintide compared to related research compounds

Cagrilintide is the only compound in this group that is not an incretin analogue. The other three are graded by how many incretin receptors they engage; cagrilintide sits outside that series on a separate hormone system.

The cagrilintide and semaglutide figures are drawn from the same trial, REDEFINE 1, and are directly comparable. The tirzepatide and retatrutide figures are drawn from separate clinical trials and are not head-to-head comparisons. Approval status refers to the licensed medicines. All compounds are supplied by Crystal Peptides strictly as research reagents.

Read the table by pathway rather than by percentage. Semaglutide, tirzepatide and retatrutide are the same idea at increasing scale: one incretin receptor, then two, then three. Cagrilintide is a different idea. It produces less weight loss on its own than any of them, and that is not the comparison the research base makes. The comparison it makes is what happens when an amylin analogue is added on top of an incretin, which in REDEFINE 1 was roughly a six to seven point gain over semaglutide alone.

Quality and testing

Every batch is tested by HPLC and independently verified through Janoshik analytical testing, with a batch-specific Certificate of Analysis. Counterfeit and generic collective COAs are widespread in this market. Batch-level third-party verification against a named laboratory is the only reliable check.

Amylin analogues carry a specific failure mode that a purity figure will not surface. The parent hormone aggregates into amyloid fibrils, and although the proline substitutions in cagrilintide suppress that tendency, material that has been agitated, heat-stressed or repeatedly freeze-thawed in transit can carry aggregate that a chromatogram run on fresh material never saw. Handling matters here in a way it does not for most small peptides.

Regulatory and legal

All products supplied by Crystal Peptides are intended strictly for research and development use. These materials are provided for laboratory investigation and are not supplied for use in humans or animals.

This product is not a drug, food, dietary supplement, medical device or cosmetic. Cagrilintide is not authorised as a medicinal product by the European Medicines Agency, the U.S. Food and Drug Administration, or any other national regulator. CagriSema, the fixed combination of cagrilintide and semaglutide, is under FDA review following submission in December 2025 and is not approved in the US or EU. Semaglutide is separately approved as a medicine under licensed brands; that approval attaches to those licensed products and not to research material. Any statements regarding the compound are drawn from published scientific research and have not been evaluated by any regulatory authority. These materials are not intended to diagnose, treat, cure or prevent any disease.

Materials must be handled only by qualified professionals trained in laboratory research procedures. Introduction of this product into humans or animals is prohibited and may breach applicable laws and regulations. Purchasers are responsible for ensuring that all use, storage, handling and disposal complies with applicable national and local regulations. Rules on the purchase and import of research chemicals differ by country.

LABORATORY REAGENT, FOR RESEARCH PURPOSES ONLY. Not a drug or food. Not for human consumption.

Sources and references

• Kruse T, Hansen JL, Dahl K, et al. Development of Cagrilintide, a Long-Acting Amylin Analogue. Journal of Medicinal Chemistry. 2021;64(15):11183-11194. PMID: 34288673
• Lau DCW, Erichsen L, Francisco AM, et al. Once-weekly cagrilintide for weight management in people with overweight and obesity: a multicentre, randomised, double-blind, placebo-controlled and active-controlled, dose-finding phase 2 trial. The Lancet. 2021;398(10317):2160-2172. PMID: 34798060
• Fletcher MM, Keov P, Truong TT, et al. AM833 Is a Novel Agonist of Calcitonin Family G Protein-Coupled Receptors: Pharmacological Comparison with Six Selective and Nonselective Agonists. Journal of Pharmacology and Experimental Therapeutics. 2021;377(3):417-440.
• Enebo LB, Berthelsen KK, Kankam M, et al. Safety, tolerability, pharmacokinetics, and pharmacodynamics of concomitant administration of multiple doses of cagrilintide with semaglutide 2.4 mg for weight management: a randomised, controlled, phase 1b trial. The Lancet. 2021;397(10286):1736-1748.
• Frias JP, Deenadayalan S, Erichsen L, et al. Efficacy and safety of co-administered once-weekly cagrilintide 2.4 mg with once-weekly semaglutide 2.4 mg in type 2 diabetes: a multicentre, randomised, double-blind, active-controlled, phase 2 trial. The Lancet. 2023;402(10403):720-730.
• Garvey WT, Bluher M, Osorto Contreras CK, et al. Coadministered Cagrilintide and Semaglutide in Adults with Overweight or Obesity (REDEFINE 1). New England Journal of Medicine. 2025.
• Davies M, et al. Cagrilintide-Semaglutide in Adults with Type 2 Diabetes and Overweight or Obesity (REDEFINE 2). New England Journal of Medicine. 2025.
• Structural and dynamic features of cagrilintide binding to calcitonin and amylin receptors. Nature Communications. 2025. doi:10.1038/s41467-025-58680-y
• Novo Nordisk. Novo Nordisk files for FDA approval of CagriSema. 18 December 2025.
• PubChem Compound Summary for CID 171397054, Cagrilintide. National Center for Biotechnology Information.

Frequently Asked Questions

What is Cagrilintide?

Cagrilintide (AM833) is a long-acting synthetic analogue of amylin developed by Novo Nordisk. Unlike incretin peptides such as semaglutide, tirzepatide, and retatrutide, cagrilintide acts primarily through the amylin receptor system together with the calcitonin receptor. It is supplied by Crystal Peptides exclusively for laboratory research and development and is not an approved medicinal product.

Why is Cagrilintide called AM833?

AM833 is the internal Novo Nordisk development code used throughout much of the published scientific literature, including the pharmacology studies by Fletcher et al. Other development identifiers, including NN9838 and NNC0174-0833, refer to the same investigational compound, while "Cagri" has become a common shorthand within the research community.

What is the difference between Cagrilintide and CagriSema?

Cagrilintide is a single peptide, whereas CagriSema is a fixed-dose combination containing cagrilintide and semaglutide. Because CagriSema combines two separate active molecules, it does not possess its own CAS number, molecular formula, or molecular weight. Many of the clinical outcomes quoted online for "cagrilintide" actually originate from studies investigating the CagriSema combination rather than cagrilintide alone.

Where can I buy Cagrilintide online?

Researchers within Europe can buy Cagrilintide online from Crystal Peptides as a high-purity research peptide independently tested by accredited laboratories. Every batch is accompanied by a batch-specific Certificate of Analysis (COA), allowing researchers to verify peptide identity, purity, and analytical consistency before incorporating the material into laboratory research.

How does Cagrilintide differ from Semaglutide?

The principal difference lies in the hormone systems they target. Semaglutide is a selective GLP-1 receptor agonist, whereas cagrilintide acts primarily through the amylin receptor system together with the calcitonin receptor. Because these signalling pathways are complementary rather than overlapping, researchers frequently compare the two compounds to investigate different aspects of endocrine regulation and metabolic physiology. This complementary biology also forms the scientific rationale behind the investigational fixed-dose combination known as CagriSema.

How does Cagrilintide differ from Pramlintide?

Both peptides are long-acting analogues of the naturally occurring hormone amylin and share the proline substitutions that reduce amyloid fibril formation. However, cagrilintide was engineered to achieve a substantially longer circulating half-life through reversible albumin binding, allowing once-weekly investigation in clinical research. It also demonstrates activity at the calcitonin receptor, whereas pramlintide is primarily an amylin receptor agonist. Pramlintide is an authorised medicinal product, while cagrilintide remains an investigational research compound.

Why do so many pages say Cagrilintide produces over 20% weight loss?

Much of this confusion arises because many online sources quote results from CagriSema rather than cagrilintide alone. In the Phase 3 REDEFINE 1 trial, the widely reported 22.7% mean body-weight reduction was observed in the cagrilintide plus semaglutide combination arm. The cagrilintide-only arm of the same study reported 11.8%. Distinguishing between the single peptide and the combination product is essential when interpreting published clinical research. These figures are presented solely to summarise the scientific literature and should not be interpreted as evidence of authorised therapeutic use.

Is CagriSema approved?

As of 2026, CagriSema has not been approved as a medicinal product. Novo Nordisk submitted a New Drug Application to the U.S. Food and Drug Administration in December 2025 based on the REDEFINE clinical programme, while no public confirmation of a European Medicines Agency submission has been announced. Any future approval would apply only to the licensed CagriSema product and not to research-grade cagrilintide.

Is Cagrilintide legal, and is a prescription required?

Cagrilintide remains an investigational research compound and has not been approved for human therapeutic use in any major jurisdiction. Crystal Peptides supplies cagrilintide exclusively as a laboratory research peptide rather than as a medicine. Because it is supplied for research purposes only, prescription requirements do not apply in the same way as they do for authorised medicinal products. Researchers are responsible for ensuring that the purchase, importation, possession, and use of research compounds comply with the laws applicable within their own country.

Is Cagrilintide banned in sport?

Effectively yes. Because cagrilintide is not an approved medicinal product, it falls within the World Anti-Doping Agency (WADA) category covering non-approved substances (S0), which are prohibited both in and out of competition. It should not be used by athletes subject to anti-doping regulations.

How should Cagrilintide be reconstituted and stored?

Cagrilintide is supplied as a lyophilised peptide and is typically reconstituted using sterile water or bacteriostatic water introduced slowly down the inside wall of the vial. The solution should be allowed to dissolve naturally without vigorous agitation or vortexing, as excessive mechanical stress may promote aggregation in amylin-family peptides. Lyophilised vials should be stored at -20°C or below, protected from light and moisture. Following reconstitution, solutions should generally be refrigerated at 2–8°C and protected from repeated freeze-thaw cycles.

Is Crystal Peptides Cagrilintide third-party tested?

Yes. Every batch of cagrilintide supplied by Crystal Peptides undergoes independent third-party analytical testing and is accompanied by a batch-specific Certificate of Analysis. Researchers can review the COA to verify peptide identity, purity, and analytical quality for the exact batch supplied, providing the transparency and traceability expected for laboratory research.

Do you ship Cagrilintide across Europe?

Yes. Crystal Peptides ships cagrilintide throughout Europe using discreet packaging and tracked delivery services. Information regarding shipping destinations, estimated delivery times, and available delivery options can be found on the Shipping Information page.