Trust Signals
Key Takeaways
- Cagrilintide is an amylin receptor agonist with a half-life of roughly 7-8 days, enabling once-weekly subcutaneous dosing.
- The best monotherapy evidence comes from Enebo et al. (Lancet, 2021, n=706): 2.4 mg/week produced approximately 10.8% weight loss at 26 weeks versus 3.0% for placebo.
- Cagrilintide is not FDA-approved as of mid-2026; it is sold by research vendors for non-human research use only.
- Research-grade vials typically run $150-$350 for 5 mg; always verify purity with a third-party HPLC and mass-spec COA before purchase.
- The long half-life is a double-edged feature: nausea and GI side effects can persist for days after dosing, unlike shorter-acting peptides.
What Is Cagrilintide and Should You Buy It?
Table of Contents
- How cagrilintide works: mechanism with specific numbers
- Evidence ledger: what the trials actually show
- Can you legally buy cagrilintide?
- Cagrilintide cost: what you should expect to pay
- What most pages get wrong about cagrilintide
- How to judge a cagrilintide vendor and COA
- Storage and stability: the chemistry behind the rules
- Reconstitution and dosing math
- Honest head-to-head: cagrilintide vs. alternatives
- Frequently asked questions
- Sources
How Cagrilintide Works: Mechanism With Specific Numbers
Cagrilintide is a fatty-acid acylated analogue of human amylin (islet amyloid polypeptide, IAPP). Native amylin has a half-life of roughly 13 minutes. Cagrilintide's C18 fatty-diacid acylation and amino-acid substitutions extend that to approximately 7-8 days, confirmed in Phase 1 pharmacokinetic data reviewed in the Lancet 2021 publication by Enebo et al.
Check your GLP-1 eligibility
Use our free BMI Calculator to see if you may qualify for provider-reviewed GLP-1 therapy.
Try the BMI Calculator →Primary receptor targets: AMY1 (calcitonin receptor + RAMP1), AMY2 (CTR + RAMP2), and AMY3 (CTR + RAMP3). These receptor complexes are expressed in the area postrema and nucleus tractus solitarius of the brainstem, and in the arcuate nucleus of the hypothalamus. Amylin receptor activation at these sites produces three coordinated effects:
- Delayed gastric emptying, reducing postprandial glucose excursions and extending satiety signals.
- Glucagon suppression during fed states, contributing to postprandial glucose control.
- Central satiety signaling via the hypothalamic melanocortin system, reducing caloric intake.
The molecular weight of cagrilintide is approximately 4052 Da. This figure matters for COA interpretation: a mass-spec result meaningfully different from that value indicates a different compound or a degradation product.
Evidence Ledger: What the Trials Actually Show
| Claim | Best Evidence | Source / Detail | Effect Direction | Confidence |
|---|---|---|---|---|
| Cagrilintide 2.4 mg/week reduces body weight | Phase 2 RCT | Enebo et al., Lancet 2021; n=706 adults with obesity; 26 weeks | ~10.8% loss vs. ~3.0% placebo | Moderate |
| CagriSema combination produces additive weight loss | Phase 2 RCT | Novo Nordisk Phase 2 data; combination arm outperformed both monotherapies | Greater than either alone | Moderate |
| Once-weekly dosing enabled by ~7-8 day half-life | Phase 1 PK data | Cited in Enebo et al. supplementary | Confirmed | High |
| Nausea and GI side effects most common adverse events | Phase 2 RCT safety data | Enebo et al., Lancet 2021 | Dose-dependent increase | High |
| Improves cardiometabolic markers (lipids, BP, glucose) | Phase 2 secondary endpoints | Enebo et al., Lancet 2021 | Directionally positive | Moderate |
| Long-term cardiovascular outcome benefit | None yet | No CVOT data published as of mid-2026 | Unknown | Very low |
| Research-grade vials match clinical-grade pharmacokinetics | No published comparison | No independent study exists | Unknown | Very low |
The Moderate rating for the primary weight-loss claim reflects that 26-week Phase 2 data in roughly 700 patients is real evidence, but not Phase 3 scale or duration. The REDEFINE Phase 3 program for CagriSema is ongoing; monotherapy Phase 3 data have not been published.
Can You Legally Buy Cagrilintide?
This is meaningfully different from compounded semaglutide, which occupied a temporary gray zone under FDA shortage provisions. Cagrilintide has no approved reference product, so no compounding pathway applies.
Cagrilintide Cost: What You Should Expect to Pay
Research-grade cagrilintide pricing is not standardized. Based on publicly listed vendor prices at time of writing:
| Quantity | Typical Price Range | Cost per mg |
|---|---|---|
| 2 mg vial | $80 - $160 | $40 - $80/mg |
| 5 mg vial | $150 - $350 | $30 - $70/mg |
| 10 mg vial | $250 - $550 | $25 - $55/mg |
Price alone tells you nothing about quality. A vial priced at $400 from a vendor with no independent COA is a worse buy than a $200 vial with documented HPLC purity above 98% and mass-spec molecular weight confirmation. Pricing also shifts as peptide synthesis capacity changes, so treat these ranges as a rough benchmark only.
What Most Pages Get Wrong About Cagrilintide
1. Conflating Phase 2 with approved-drug evidence. Most buy-review pages present the 10.8% weight loss figure as if it settles the question. It does not. Phase 2 trials optimize dose-finding; they are not powered for the safety and efficacy confirmations that Phase 3 demands. Semaglutide's Phase 2 weight data also looked compelling, and Phase 3 confirmed them, but that outcome is not guaranteed.
2. Ignoring the half-life as a risk amplifier. The 7-8 day half-life is presented as a convenience feature. It is also a toxicity duration feature. If nausea, vomiting, or a more serious reaction occurs, the plasma concentration cannot be reversed quickly. This is categorically different from a peptide with a 30-minute half-life. Research users who experience GI effects may remain symptomatic for days.
3. Treating research-grade and pharmaceutical-grade as equivalent. Novo Nordisk's clinical material is manufactured under GMP with endotoxin testing, sterility testing, and batch-to-batch consistency documentation. Research peptide vendors may provide HPLC data but rarely meet the same standard. No published study has characterized the pharmacokinetics of commercially available research-grade cagrilintide, meaning its real-world half-life and potency in that form are unverified.
4. Missing the acylation degradation pathway. The fatty-acid chain responsible for albumin binding and half-life extension is susceptible to hydrolysis and oxidation. See the storage section below for why this matters to buyers.
How to Judge a Cagrilintide Vendor and COA
A certificate of analysis (COA) is only as credible as the laboratory that produced it. Apply this checklist:
| COA Element | Minimum Standard | Red Flag |
|---|---|---|
| HPLC purity | Greater than 98% | No chromatogram shown; purity listed without method |
| Molecular weight (MS) | Matches ~4052 Da | No mass spec data at all |
| Endotoxin test | Below 1 EU/mg (LAL method) | Not mentioned; "sterile" claimed without testing |
| Lab independence | Third party, named lab | COA issued by vendor's own "in-house lab" |
| COA date | Batch-specific, within 12 months | Undated; single COA covers all product lines |
| Peptide sequence confirmation | MS/MS or sequencing note | Absent entirely |
Ask the vendor directly: "Can you name the third-party laboratory that performed this analysis?" A vendor who cannot answer that question has not actually done independent testing.
Storage and Stability: The Chemistry Behind the Rules
Why freeze lyophilized peptides: In the lyophilized (freeze-dried) state, cagrilintide's amide backbone is protected from hydrolysis by the absence of bulk water. At room temperature, trace moisture catalyzes peptide bond cleavage. The acylated fatty-acid chain is additionally vulnerable to oxidation in the presence of oxygen and light. Both degradation pathways are thermally accelerated, meaning every degree of warmth above freezer temperature meaningfully shortens shelf life. Store lyophilized vials at -20 degrees C, protected from light.
Why do not shake reconstituted peptide: Mechanical agitation generates air-water interfaces that denature the peptide. The acylated chain is amphiphilic: it partitions to interfaces and aggregates there. Aggregated peptide is inactive and potentially immunogenic. Swirl the vial gently instead.
Why bacteriostatic water rather than sterile water: Bacteriostatic water contains 0.9% benzyl alcohol, which inhibits microbial growth and extends the reconstituted peptide's usable life to roughly 28 days refrigerated. Sterile water without a preservative supports microbial growth within days at 4 degrees C and should not be used for multi-dose vials.
Freeze-thaw cycling: Each freeze-thaw cycle risks ice crystal formation that physically disrupts peptide structure and the fatty-acid acylation linkage. Aliquot vials before freezing if you need multiple doses from one batch.
Reconstitution and Dosing Math
These calculations apply to research-grade lyophilized vials. They are provided for informational purposes for legitimate researchers only.
| Vial Size | Bacteriostatic Water to Add | Resulting Concentration | Volume for 2.4 mg (Phase 2 dose) |
|---|---|---|---|
| 5 mg | 5 mL | 1 mg/mL (1000 mcg/mL) | 2.4 mL |
| 5 mg | 2.5 mL | 2 mg/mL | 1.2 mL |
| 10 mg | 10 mL | 1 mg/mL | 2.4 mL |
Inject bacteriostatic water slowly down the interior wall of the vial, not directly onto the lyophilized cake. Wait for the cake to dissolve fully (typically 1-3 minutes of gentle swirling). Do not use if the solution is cloudy after full mixing, as this indicates aggregation or contamination.
Honest Head-to-Head: Cagrilintide vs. Alternatives
| Factor | Cagrilintide (research) | Semaglutide 2.4 mg (Wegovy) | Tirzepatide 15 mg (Zepbound) |
|---|---|---|---|
| Approval status | None | FDA-approved (2021) | FDA-approved (2023) |
| Best published weight loss | ~10.8% at 26 weeks (Phase 2) | ~14.9% at 68 weeks (STEP 1, n=1961) | ~20.9% at 72 weeks (SURMOUNT-1, n=2539) |
| Evidence quality | Phase 2 only | Multiple Phase 3 RCTs | Multiple Phase 3 RCTs |
| Mechanism | Amylin receptor agonism | GLP-1 receptor agonism | GIP + GLP-1 dual agonism |
| Half-life | ~7-8 days | ~7 days | ~5 days |
| CVOT safety data | None published | SELECT trial (CV benefit shown) | SURPASS-CVOT (non-inferiority shown) |
| Purity assurance | Vendor-dependent; unregulated | GMP pharmaceutical standard | GMP pharmaceutical standard |
| Where cagrilintide loses | On all regulatory, safety-data, and efficacy metrics vs. approved drugs | -- | -- |
| Where cagrilintide has potential | Complementary amylin mechanism; CagriSema combination may outperform both alone | -- | -- |
The honest conclusion: for anyone seeking weight loss treatment today, both FDA-approved options have substantially stronger evidence and guaranteed pharmaceutical-grade purity. Cagrilintide's research interest lies in its complementary mechanism and the CagriSema combination data, not in superiority to currently available drugs.
Frequently Asked Questions
What is cagrilintide and how does it work?
Cagrilintide is a long-acting amylin analogue developed by Novo Nordisk. It binds amylin receptors (AMY1-3) in the hypothalamus and brainstem to slow gastric emptying, suppress glucagon, and reduce caloric intake. Its acylated structure extends the half-life to approximately 7-8 days, enabling once-weekly dosing.
Can I legally buy cagrilintide?
Cagrilintide is not FDA-approved as of mid-2026. It is not legally available by prescription in the United States. Research vendors sell it as a research compound not for human use. Importing unapproved drugs carries legal and health risks. Consult a licensed prescriber before attempting to obtain it.
What does cagrilintide cost from research vendors?
Research-grade cagrilintide typically ranges from roughly $40 to $100+ per milligram depending on quantity, vendor, and purity claims. A typical 5 mg vial runs $150-$350. Always compare cost per milligram and demand a COA before purchasing.
What is CagriSema and how does it relate to cagrilintide?
CagriSema is the investigational fixed-ratio combination of cagrilintide 2.4 mg and semaglutide 2.4 mg being developed by Novo Nordisk. Phase 3 REDEFINE trials are ongoing. In Phase 2, the combination produced greater weight loss than either agent alone.
What does the clinical evidence show for cagrilintide alone?
The best available evidence is a Phase 2 RCT (Enebo et al., Lancet 2021, n=706) in which cagrilintide 2.4 mg once weekly produced approximately 10.8% body weight reduction over 26 weeks vs. 3.0% for placebo. This is Moderate-quality evidence because Phase 3 data for cagrilintide monotherapy are not yet published.
What are the known side effects of cagrilintide?
The most common side effects reported in Phase 2 trials are nausea, vomiting, constipation, and decreased appetite, consistent with the amylin class. Injection-site reactions occurred in a minority of participants. Severe adverse events were uncommon but the long half-life means side effects can persist for days after a dose.
How should cagrilintide research peptide be stored?
Lyophilized cagrilintide should be stored at -20 degrees C and kept away from light and moisture. Once reconstituted, use within 28 days refrigerated at 2-8 degrees C. Repeated freeze-thaw cycles degrade the acylated fatty acid chain and reduce potency, though exact degradation kinetics have not been published for research-grade material.
How do I read a cagrilintide COA to judge purity?
Look for HPLC purity above 98%, molecular weight confirmation by mass spectrometry matching approximately 4052 Da, and an endotoxin test result below 1 EU/mg. Reject any COA that is undated, unsigned by a named lab, or lacking MS data. Verify the lab is independent from the vendor.
Is cagrilintide better than semaglutide for weight loss?
As monotherapy, semaglutide 2.4 mg (Wegovy) produced approximately 14.9% weight loss over 68 weeks in STEP 1 (n=1961), while cagrilintide 2.4 mg produced roughly 10.8% over 26 weeks in Phase 2. Direct 68-week comparison data for cagrilintide monotherapy are not available. The combination CagriSema appears additive, but monotherapy cagrilintide trails semaglutide on current evidence.
What reconstitution math applies to cagrilintide vials?
For a 5 mg lyophilized vial: add 5 mL bacteriostatic water to get a 1 mg/mL solution. A 2.4 mg dose equals 2.4 mL at that concentration. Inject bacteriostatic water slowly down the vial wall; do not shake. Swirl gently and inspect for particulates before use.
Where can I find cagrilintide for sale online?
Research peptide vendors sell cagrilintide labelled for research purposes only. Quality varies enormously. Require a third-party COA with HPLC and MS data, check for independent lab verification, and avoid vendors who cannot name the testing laboratory. FormBlends provides research-use compounds with documented quality testing.
Sources
- Enebo LB, Berthelsen KK, Abuhelika G, et al. Safety, tolerability, pharmacokinetics, and pharmacodynamics of cagrilintide with semaglutide 2.4 mg for weight management in adults with overweight or obesity (SCALE): a randomised, double-blind, placebo-controlled, phase 2 trial. Lancet. 2021;397(10286):1736-1748.
- Wilding JPH, Batterham RL, Calanna S, et al. Once-weekly semaglutide in adults with overweight or obesity (STEP 1). N Engl J Med. 2021;384(11):989-1002.
- Jastreboff AM, Aronne LJ, Ahmad NN, et al. Tirzepatide once weekly for the treatment of obesity (SURMOUNT-1). N Engl J Med. 2022;387(3):205-216.
- Lincoff AM, Brown-Frandsen K, Colhoun HM, et al. Semaglutide and cardiovascular outcomes in obesity without diabetes (SELECT). N Engl J Med. 2023;389(24):2221-2232.
- Novo Nordisk. REDEFINE Phase 3 program (CagriSema): ClinicalTrials.gov identifiers NCT05669755 and related. Accessed 2026.
- Hay DL, Garelja ML, Poyner DR, Walker CS. Update on the pharmacology of calcitonin/CGRP family of peptides: IUPHAR Review 25. Br J Pharmacol. 2018;175(1):3-17. [Amylin receptor pharmacology context.]
- US Food and Drug Administration. Compounding and the FDA: Questions and Answers. FDA.gov. Accessed 2026. [For context on compounding pathway requirements.]
- Manning MC, Chou DK, Murphy BM, Payne RW, Katayama DS. Stability of protein pharmaceuticals: an update. Pharm Res. 2010;27(4):544-575. [Peptide storage and degradation chemistry.]