Cagrilintide Side Effects: What Studies Report

Overview: What the Trials Described

Cagrilintide is a long-acting amylin receptor agonist that has been investigated for weight management as a single agent and in coadministration with the GLP-1 receptor agonist semaglutide, and pipeline reviews placed it among the amylin-based agents that advanced into late-phase clinical development (PMID 40022548, PMID 41948476). Across that published record, researchers reported that gastrointestinal events dominated the adverse-event tables, that most were graded mild to moderate, and that they appeared most often while doses were being escalated in the randomised phase 2 dose-finding trial of once-weekly cagrilintide in overweight and obesity (PMID 34798060).

Evidence tier: Established. Everything summarised below is drawn from randomised phase 1b, phase 2 and phase 3 trials and from peer-reviewed systematic reviews and meta-analyses indexed in PubMed, each linked in the sentence that states the finding. This page is for educational purposes only and is not medical advice; consult a licensed physician about any medication, symptom or treatment question.

Gastrointestinal Adverse Events: What Studies Report

The phase 1b trial that administered multiple doses of cagrilintide together with once-weekly semaglutide 2·4 mg for weight management reported that adverse events were mostly mild to moderate and predominantly gastrointestinal (PMID 33894838). The same pattern recurred in the multicentre, randomised, double-blind, placebo-controlled and active-controlled phase 2 dose-finding trial, in which once-weekly cagrilintide was studied at doses from 0·3 mg to 4·5 mg over 26 weeks in people with overweight and obesity and gastrointestinal disorders were the most frequently recorded adverse events (PMID 34798060).

The specific events named in these reports were nausea, vomiting, diarrhoea and constipation, and a systematic review and meta-analysis of cagrilintide alone and in combination with semaglutide concluded that gastrointestinal adverse events — nausea and vomiting in particular — occurred more often with active treatment than with comparators (PMID 39676787). Researchers framed these as class-typical rather than unexpected: a network meta-analysis of GLP-1 receptor agonists in type 2 diabetes documented the same gastrointestinal burden across that drug class (PMID 38286487), and a clinical review of weight-management pharmacotherapy described gastrointestinal intolerance as the characteristic tolerability issue for incretin- and amylin-based agents (PMID 40865172).

Severity and timing

Severity grading matters when reading these tables. The phase 1b report characterised the events it recorded as mostly mild to moderate rather than severe (PMID 33894838), and the phase 2 dose-finding trial reached the same conclusion across its 26-week treatment period (PMID 34798060). Because those trials escalated doses stepwise under protocol, the published data describe events observed within a supervised escalation schedule and not events observed under any other pattern of administration.

Cagrilintide With Semaglutide: What Studies Report

Much of the safety literature concerns the fixed combination of cagrilintide with semaglutide rather than cagrilintide on its own. A multicentre, randomised, double-blind, active-controlled phase 2 trial in type 2 diabetes compared once-weekly cagrilintide 2·4 mg coadministered with once-weekly semaglutide 2·4 mg against semaglutide 2·4 mg alone and reported that the adverse events were predominantly gastrointestinal, in line with the profile already established for semaglutide (PMID 37364590).

Two phase 3 trials extended that picture. In adults with overweight or obesity, the study of coadministered cagrilintide and semaglutide reported substantially greater mean body-weight reduction than placebo over 68 weeks, with gastrointestinal adverse events the most common category and most graded mild to moderate (PMID 40544433). In adults with overweight or obesity and type 2 diabetes, researchers likewise reported greater weight reduction than placebo alongside gastrointestinal events as the leading adverse-event category (PMID 40544432). Reviews of the obesity pipeline summarised these combination results as the basis for continued late-phase evaluation (PMID 40022548).

Findings Beyond the Gut: What Studies Report

Published reports did not describe gastrointestinal events as the only monitored outcome. In populations with type 2 diabetes, glycaemic safety was an explicit part of the assessment: the phase 2 type 2 diabetes trial measured glycated haemoglobin change alongside safety endpoints when cagrilintide 2·4 mg was added to semaglutide 2·4 mg (PMID 37364590), and the phase 3 trial in adults with overweight or obesity and type 2 diabetes assessed both glycaemic and weight outcomes with safety reporting (PMID 40544432). A review of amylin analogues for obesity without diabetes discussed tolerability as the principal constraint on this class and noted injection-related and gastrointestinal effects among the issues carried forward from earlier amylin agents (PMID 39317404).

Treatment discontinuation

Discontinuation because of adverse events is the practical endpoint that trial readers often look for. The meta-analysis of cagrilintide alone and in combination reported that adverse-event-related discontinuation was part of the pooled safety assessment and that gastrointestinal events drove the difference versus comparators (PMID 39676787). The phase 3 trial in adults with overweight or obesity reported discontinuation and safety outcomes over the full 68-week treatment period (PMID 40544433).

Trial-by-Trial Summary

How Long Does Cagrilintide Last?

Dosing interval in the published trials

Every randomised trial in the verified record administered cagrilintide on a once-weekly schedule: the phase 2 dose-finding trial was explicitly a trial of once-weekly cagrilintide in overweight and obesity (PMID 34798060), and the phase 2 type 2 diabetes trial coadministered once-weekly cagrilintide 2·4 mg with once-weekly semaglutide 2·4 mg (PMID 37364590). The phase 1b trial that characterised pharmacokinetics and pharmacodynamics supported that weekly interval when cagrilintide was given with semaglutide 2·4 mg (PMID 33894838). In other words, when the literature speaks about how long cagrilintide "lasts", it is describing a long-acting amylin analogue designed for weekly rather than daily administration — a design feature that reviews of the amylin class have highlighted as a departure from earlier short-acting agents (PMID 39317404).

Treatment duration studied

The longest exposures in the verified record are the 68-week phase 3 programmes in adults with overweight or obesity (PMID 40544433) and in adults with overweight or obesity and type 2 diabetes (PMID 40544432), compared with 26 weeks in the earlier dose-finding trial (PMID 34798060). Safety statements therefore describe those windows, not indefinite use.

Shelf-life and in-use storage questions

A separate question often raised alongside duration of action concerns how long a supply remains usable once a vial or pen has been opened and put into use. The peer-reviewed trial reports summarised here were designed to answer efficacy and safety questions and did not publish in-use storage intervals; study product was supplied and handled under protocol, and the publications report clinical endpoints instead (PMID 33894838, PMID 34798060). For any authorised medicine, storage temperature, in-use periods and expiry dating are specified in the approved product labelling and by the dispensing pharmacy, not in the clinical literature — so those documents, rather than a trial abstract, are where such details live.

How Amylin Analogues Compare in the Literature

Cagrilintide is not the only amylin receptor agonist under study. A review of amylin analogues for obesity without diabetes set out the present and future of the class and discussed how tolerability shapes its development (PMID 39317404), while a discovery-to-proof-of-concept report on eloralintide described a further amylin receptor agonist advancing through early clinical evaluation (PMID 41109426). A broader perspective on multi-receptor agonists and next-generation metabolic modulators placed amylin–incretin combinations within the wider obesity pharmacotherapy landscape and noted the controversies that accompany rapid pipeline expansion (PMID 41948476).

Limitations of the Published Safety Record

• Trial populations are selective. The randomised evidence comes from enrolled adults meeting entry criteria in weight-management and type 2 diabetes trials (PMID 40544432, PMID 40544433).
• Much of the safety data is combination data. Several key reports studied cagrilintide together with semaglutide 2·4 mg, which makes attribution of individual events to one component difficult (PMID 37364590).
• Pooled estimates carry heterogeneity. The meta-analysis pooling cagrilintide and combination trials reported gastrointestinal risk increases across studies of differing design and duration (PMID 39676787).
• Class context is still evolving. Reviews described the amylin and incretin field as fast-moving, with comparative safety questions still open (PMID 40022548, PMID 40865172).

Regulatory and Trademark Notes

Cagrilintide has been evaluated in company-sponsored randomised trials, and reviews of the pipeline described it as an agent in late-phase clinical development for obesity rather than a long-established therapy (PMID 40022548). Any brand name applied to the cagrilintide–semaglutide combination is a trademark of its owner, and PeptideU is an independent educational publisher that is not affiliated with or endorsed by any manufacturer, sponsor or trademark holder referenced on this page. Nothing here describes availability, supply or administration.

Related Learning

This page covers the adverse-event and safety literature only. For structured background on amylin signalling, trial design and how the combination programme developed, the cagrilintide course teaches that material separately without repeating the safety tables above.

References

• 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 (Lancet, 2021)
• 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 (Lancet, 2021)
• 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 (Lancet, 2023)
• Comparative effectiveness of GLP-1 receptor agonists on glycaemic control, body weight, and lipid profile for type 2 diabetes: systematic review and network meta-analysis (BMJ, 2024)
• Amylin analogs for the treatment of obesity without diabetes: present and future (Expert Review of Clinical Pharmacology, 2024)
• Efficacy and Safety of Cagrilintide Alone and in Combination with Semaglutide (Cagrisema) as Anti-Obesity Medications: A Systematic Review and Meta-Analysis (Indian Journal of Endocrinology and Metabolism, 2024)
• The promise of glucagon-like peptide 1 receptor agonists (GLP-1RA) for the treatment of obesity: a look at phase 2 and 3 pipelines (Expert Opinion on Investigational Drugs, 2025)
• Cagrilintide-Semaglutide in Adults with Overweight or Obesity and Type 2 Diabetes (New England Journal of Medicine, 2025)
• Coadministered Cagrilintide and Semaglutide in Adults with Overweight or Obesity (New England Journal of Medicine, 2025)
• Weight management treatment in obesity (Medicina Clinica, 2025)
• Eloralintide (LY3841136), a novel amylin receptor agonist for the treatment of obesity: From discovery to clinical proof of concept (Molecular Metabolism, 2025)
• Obesity pharmacotherapy reimagined: The era of multi-receptor agonists and next-generation metabolic modulators, perspectives and controversies (Metabolism Open, 2026)