What Cagrilintide is

Cagrilintide belongs to the incretin-mimetic class of investigational peptides — a rapidly expanding family of injectable compounds that target the gut-hormone signaling axis to regulate appetite, gastric emptying, insulin release, and energy expenditure. The class has produced the largest weight-reduction results ever reported in metabolic drug trials, and the pipeline of second- and third-generation molecules is now some of the most closely watched research in endocrinology.

Cagrilintide is a long-acting amylin analogue. On its own it modestly reduces food intake; combined with semaglutide as CagriSema, Phase 3 data show weight loss competitive with tirzepatide.

Mechanism of action

The class targets one or more of three receptors expressed on pancreatic β-cells, on hypothalamic neurons that regulate food intake, and on peripheral tissues that regulate energy expenditure:

• GLP-1 receptor — glucose-dependent insulin secretion, slowed gastric emptying, and central satiety signaling.
• GIP receptor — potentiation of postprandial insulin release, effects on adipose tissue insulin sensitivity, and (in the newer literature) modulation of nausea pathways that partially explain why dual/triple agonists appear better tolerated at high doses than mono-agonist regimens.
• Glucagon receptor — increased resting energy expenditure and hepatic fatty-acid oxidation, the pathway most closely associated with the outsized weight-loss magnitude of triple agonists like retatrutide.

Structurally, modern incretin peptides carry a fatty-acid side chain that binds serum albumin. Albumin binding is what extends half-life from minutes (native GLP-1, ≈ 2 minutes) to days (semaglutide ≈ 165 h, tirzepatide ≈ 120 h, retatrutide ≈ 6 days), enabling once-weekly subcutaneous dosing in clinical trials.

Published research findings

• Retatrutide — Phase 2 (Jastreboff et al., NEJM 2023, NCT04881760): 48-week mean weight reduction of approximately 24.2% at the 12 mg dose in adults with obesity and no diabetes. Adverse events were primarily gastrointestinal and titration-responsive.
• Tirzepatide — SURPASS (T2D) and SURMOUNT (obesity) trials: 72-week weight reduction of approximately 20.9% at the 15 mg dose in SURMOUNT-1.
• Semaglutide — STEP-1 (Wilding et al., NEJM 2021): 68-week weight reduction of approximately 14.9% at 2.4 mg weekly in adults with obesity.
• CagriSema — REDEFINE-1 (2024/2025 readouts): weight reduction of approximately 22.7% at 68 weeks with cagrilintide 2.4 mg + semaglutide 2.4 mg weekly.

Head-to-head data across compounds are still limited; most comparisons rely on cross-trial inference, which has known limitations (different populations, run-in periods, and titration schedules).

Dosing ranges reported in the research literature

Titration is universal in this class — every compound above starts at a very low weekly dose and steps up over 12–20 weeks to reduce gastrointestinal adverse events. Dosing figures below are reproduced from published clinical-trial protocols and are provided as literature reference only, not as protocol recommendations.

• Retatrutide (Phase 2 published protocol): 2 mg / 4 mg / 8 mg / 12 mg weekly, escalated every 4 weeks.
• Tirzepatide (SURMOUNT-1 protocol): 2.5 mg starting → 5, 7.5, 10, 12.5, 15 mg maximum, escalated every 4 weeks.
• Semaglutide (STEP-1 protocol): 0.25 mg → 0.5, 1.0, 1.7, 2.4 mg maximum, escalated every 4 weeks.
• CagriSema (REDEFINE): cagrilintide and semaglutide co-titrated to 2.4 mg / 2.4 mg weekly.

Injection is subcutaneous — abdomen, thigh, or upper arm — in published protocols.

Adverse events reported in trials

The gastrointestinal profile of the class is consistent and dose-dependent: nausea, diarrhea, constipation, decreased appetite (usually the intended effect), and occasional vomiting. Most events are mild-to-moderate and titration-responsive. Trial dropouts due to GI adverse events range roughly 4–7% across the class at highest doses.

Non-GI signals reported in one or more trials: gallbladder events, injection-site reactions, transient heart-rate elevation, and (rare) pancreatitis. Preclinical rodent thyroid C-cell findings triggered the medullary-thyroid-cancer boxed warnings on approved products; that signal has not been reproduced in humans.

Standard laboratory handling

Every research vial from PX1 is a lyophilized (freeze-dried) powder sealed under vacuum in a Type-I borosilicate vial with a butyl-rubber stopper and aluminum crimp seal. Correct handling preserves potency and prevents peptide-bond hydrolysis that degrades the active molecule.

• Storage before reconstitution: 2–8 °C refrigerator is ideal; freezer (−20 °C) for storage beyond six months. Short excursions to room temperature during shipping do not compromise integrity — the compound is stable in its solid state.
• Reconstitution solvent: bacteriostatic water for injection (0.9% benzyl alcohol) is standard for research protocols that require multiple sampling events from the same vial. Sterile water is acceptable for single-use protocols.
• Reconstitution technique: inject the diluent slowly against the vial wall — never directly onto the lyophilized cake. Swirl gently; do not shake. Shaking introduces air, denatures peptide secondary structure, and can create insoluble aggregates.
• Post-reconstitution storage: 2–8 °C refrigerated, typically stable 21–30 days depending on the peptide. Freezing a reconstituted solution repeatedly is not recommended — freeze/thaw cycles are the single biggest driver of loss-of-potency in the research literature.
• Concentration math: volume of diluent (mL) = peptide mass (mg) ÷ desired concentration (mg/mL). Example: 10 mg vial + 2 mL bacteriostatic water = 5 mg/mL.

Purity, identity and COA verification

The single most important due-diligence step when sourcing Cagrilintide for research is reviewing the lot-specific Certificate of Analysis (COA). A credible COA contains:

1. HPLC purity value with chromatogram — target ≥ 98% for injectable-grade research peptides; ≥ 99% for the newest generation of GLP/incretin compounds. A single well-defined main peak with baseline separation from impurities is what you are looking for.
2. Identity confirmation by mass spectrometry — LC-MS or MALDI-TOF confirming the observed molecular weight matches the theoretical mass to within instrument tolerance.
3. Endotoxin (LAL / kinetic-chromogenic) result — expressed in EU/mg; USP guidance for parenteral products is well below 5 EU/kg body-weight equivalent, and reputable suppliers report < 10 EU/mg on the COA.
4. Sterility result — USP <71> membrane filtration or direct inoculation, both bacterial and fungal.
5. Karl Fischer moisture — target < 5% residual water for a properly lyophilized cake.
6. Residual-solvent screen — DMF, TFA, DCM, acetonitrile below ICH Q3C thresholds.

PX1 publishes lot-specific COAs at /purity-reports. If you have received a shipment and want to verify the exact lot documentation for Cagrilintide, cross-reference the lot number on the vial label to the COA PDF.

Why researchers choose PX1 for Cagrilintide

• 100% U.S. synthesis, lyophilization, and fill/finish. No repackaged imports. Every step from raw amino acid to sealed vial happens under one U.S. GMP-compliant roof.
• Third-party ISO-17025 testing on every lot. Purity, identity, endotoxin, sterility, moisture, and residual-solvent testing performed by an independent analytical laboratory whose data appears on the shipped COA.
• Chain-of-custody documentation from raw material through final QC — the same documentation package a clinical CDMO would provide.
• Same-day shipping on in-stock catalog items ordered before 3 p.m. ET, with insulated packaging and cold-pack where appropriate.

Common researcher questions

Q: How do I know the vial contents match the label? Compare the lot number on the vial to the lot number on the COA. The COA lists HPLC purity, identity by mass-spec, and endotoxin. If any of the three is missing or the lot doesn't match, don't proceed.

Q: Can I use bacteriostatic water past its printed expiration? Bacteriostatic water carries a manufacturer-assigned expiration for the sealed vial. Once punctured, USP guidance limits multi-dose vials to 28 days at 2–8 °C. Beyond 28 days, discard.

Q: Is refrigeration required during shipping? For most lyophilized peptides, no — the solid form is stable at ambient temperature for weeks. Some compounds (IGF-1 LR3, certain GH-releasing peptides) benefit from cold-chain shipping. PX1 uses insulated packaging for temperature-sensitive lines.

Q: What if the reconstituted solution is cloudy? Cloudiness indicates aggregation or precipitation and the solution should not be used. Common causes: over-vigorous shaking, incompatible diluent, or a vial that has passed its stability window.

Research use disclaimer

Cagrilintide is supplied to licensed research professionals for in vitro and in vivo laboratory research only. Products are not intended for human consumption, veterinary use, diagnostic use, therapeutic use, or as a food additive or cosmetic. Nothing on this page constitutes medical advice. Consult the primary literature — clinical-trial registrations, peer-reviewed publications — before designing any protocol. Compounds discussed here are investigational; several have not received FDA approval for any indication.

Additional PX1 references

• Complete research library
• Lot-specific purity reports
• Product catalog
• Manufacturing & QC standards