Cagrilintide vs Semaglutide: What the Research Shows

Cagrilintide and semaglutide are often mentioned in the same breath, but they are not two versions of the same thing. Semaglutide is a GLP-1 receptor agonist — an analogue of an incretin hormone released by the gut after eating — and one of the most extensively studied peptides in clinical science, with approved pharmaceutical forms and dedicated outcome trials in cardiovascular and kidney disease [9][10][15][16]. Cagrilintide is an investigational analog of amylin, a pancreatic hormone co-secreted with insulin, acting on an entirely different receptor family in a different part of the brain [1][2]. The two are complementary rather than competing mechanisms, which is exactly why Novo Nordisk built CagriSema — a co-administration of both at 2.4 mg once weekly — and took it through the phase 3 REDEFINE program to an FDA filing [6][8]. This page compares the published trial records of each compound and summarizes the combination data. As with every article in this library, it describes research findings, not medical guidance.

For full study indexes, see the individual articles on cagrilintide and semaglutide.

Side-by-Side Overview

Two Different Hormone Systems

The interesting part of this comparison is mechanistic. These compounds do not act on the same pathway, the same receptors, or even primarily the same brain regions.

Semaglutide activates the GLP-1 receptor, mimicking an incretin hormone released by intestinal L-cells after meals. In the trial literature this produces glucose-dependent insulin secretion, glucagon suppression, slowed gastric emptying, and — via GLP-1 receptors in appetite-regulating regions of the brain — increased satiety and reduced hunger between meals [9][10].

Cagrilintide activates amylin receptors, which are themselves unusual biology: a calcitonin receptor core complexed with receptor activity-modifying proteins (RAMP1–3). Amylin acts on the area postrema in the hindbrain and downstream brainstem-hypothalamic circuits to promote meal-ending satiation — reducing meal size — rather than primarily suppressing between-meal appetite [1][2].

That satiation-versus-satiety distinction, drawn in the amylin pharmacology literature, is the core rationale for combining the mechanisms: the pathways offer a rationale for complementary effects, without establishing strictly separate circuits or proving pharmacological additivity [1]. Both hormones also slow gastric emptying and suppress post-meal glucagon, so the overlap is not zero — which is consistent with the gastrointestinal side-effect profiles looking similar across both trial programs [1][3][10].

Monotherapy Trials, Compared Carefully

The standard caveat applies with full force here: these results come from different trials with different populations, durations, background interventions, and statistical estimands. Cross-trial comparisons frame the landscape; they do not rank the compounds.

• Cagrilintide's phase 2 dose-finding trial randomized 706 adults without diabetes to once-weekly cagrilintide, once-daily liraglutide 3.0 mg, or placebo for 26 weeks. Weight reductions were dose-dependent, 6.0–10.8% versus 3.0% with placebo, and the 4.5 mg dose outperformed liraglutide (10.8% vs 9.0%, p=0.03). Notably, weight had not plateaued by week 26 [3].
• Semaglutide's STEP program ran phase 3 scale and duration: STEP 1 reported about −14.9% versus −2.4% placebo at 68 weeks in 1,961 adults [10]; STEP 2 found smaller but still superior reductions in type 2 diabetes [11]; STEP 5 showed −15.2% maintained at 104 weeks [12]; and STEP 8 beat liraglutide head-to-head (−15.8% vs −6.4%) [13].

The honest summary: cagrilintide's 26-week phase 2 number (10.8%) and semaglutide's 68-week phase 3 number (~14.9%) are not directly comparable — different durations, trial phases, and populations — and the phase 2 result is not the whole cagrilintide evidence base: later studies included cagrilintide-alone arms over 32 and 68 weeks [5][6]. Semaglutide's evidence base simply runs far deeper, extending beyond weight to cardiovascular outcomes (SUSTAIN-6, SELECT) and kidney disease progression (FLOW) [14][15][16] — territory the cagrilintide literature has not yet reached.

Is There a Head-to-Head?

The cited studies include both monotherapies, but their primary objectives concern the combination rather than a definitive comparison of cagrilintide alone with semaglutide alone. Cagrilintide's phase 2 trial used liraglutide 3.0 mg, not semaglutide, as its active comparator [3].

The closest thing to same-trial context comes from studies that happened to include both as monotherapy arms. REDEFINE 1 randomized participants to CagriSema, semaglutide 2.4 mg alone, cagrilintide 2.4 mg alone, or placebo: the monotherapy arms came in at approximately −14.9% and −11.5% respectively over 68 weeks [6]. The 32-week phase 2 trial in type 2 diabetes showed the reverse ordering on weight (−5.1% with semaglutide alone vs −8.1% with cagrilintide alone) alongside a larger HbA1c reduction with semaglutide (−1.8 vs −0.9 percentage points) [5]. These arms existed to benchmark the combination, not to compare the monotherapies against each other, so they should be read as context rather than verdicts.

CagriSema: Where the Two Compounds Actually Meet

The real clinical convergence of these two molecules is co-administration, and the numbers explain why the program exists.

The early signal came from a 2021 phase 1b trial: cagrilintide 2.4 mg added to semaglutide 2.4 mg produced 17.1% mean weight loss in just 20 weeks, versus 9.8% with placebo plus semaglutide — with neither compound meaningfully altering the other's pharmacokinetics [4].

The phase 3 REDEFINE program then delivered the pivotal data:

• REDEFINE 1 (3,417 adults without diabetes, 68 weeks): estimated mean weight change −20.4% with CagriSema versus −3.0% with placebo under the treatment-policy estimand, with the semaglutide and cagrilintide monotherapy arms at roughly −14.9% and −11.5%. In analyses assuming full adherence, mean reduction reached 22.7%, and 40.4% of participants lost at least 25% of body weight. Gastrointestinal adverse events affected 79.6% versus 39.9% with placebo, mostly transient and mild-to-moderate [6].
• REDEFINE 2 (1,206 adults with type 2 diabetes, 68 weeks): −13.7% versus −3.4% with placebo, and 73.5% of treated participants reached an HbA1c of 6.5% or below versus 15.9% [7].
• REDEFINE 4 (open-label, 84 weeks, vs tirzepatide 15 mg): CagriSema's 20.2% did not achieve non-inferiority against tirzepatide's 23.6% — a miss worth knowing about when reading enthusiastic summaries of the combination [17].

In both trials that included all three arms — REDEFINE 1 and the phase 2 diabetes trial — the combination exceeded what either monotherapy arm produced in the same study [5][6] — the clearest available evidence that amylin agonism and GLP-1 receptor agonism are additive mechanisms rather than redundant ones. Novo Nordisk filed CagriSema with the FDA in December 2025; no approval has been announced as of this writing [8].

Bottom Line for Researchers

This is not a rivalry between two drugs in the same class. Semaglutide is an approved, deeply characterized GLP-1 receptor agonist with outcome-trial evidence; cagrilintide is an investigational amylin analog with a phase 2 monotherapy readout and component-arm evidence extending to 68 weeks. The published literature treats them less as alternatives than as components — different hormone systems whose combination produced larger mean weight reductions than the component arms in the cited trials. The open questions now belong mostly to the combination: regulatory outcome, durability, body composition, and cardiovascular endpoints in the ongoing REDEFINE 3 trial.

Corrections

2026-09-09: The evidence table and discussion now acknowledge the 32- and 68-week monotherapy component arms; the previous text incorrectly stated that no longer-term monotherapy dataset existed.

References

1. Hay DL, Chen S, Lutz TA, Parkes DG, Roth JD. Amylin: Pharmacology, Physiology, and Clinical Potential. Pharmacol Rev. 2015;67(3):564–600. doi:10.1124/pr.115.010629. PMID: 26071095
2. Kruse T, et al. Development of Cagrilintide, a Long-Acting Amylin Analogue. J Med Chem. 2021;64(15):11183–11194. doi:10.1021/acs.jmedchem.1c00565. PMID: 34288673
3. Lau DCW, 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. Lancet. 2021;398(10317):2160–2172. doi:10.1016/S0140-6736(21)01751-7. PMID: 34798060
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5. Frias JP, 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. Lancet. 2023;402(10403):720–730. doi:10.1016/S0140-6736(23)01163-7. PMID: 37364590
6. Garvey WT, et al. Coadministered Cagrilintide and Semaglutide in Adults with Overweight or Obesity (REDEFINE 1). N Engl J Med. 2025;393(7):635–647. doi:10.1056/NEJMoa2502081. PMID: 40544433
7. Davies MJ, et al. Cagrilintide–Semaglutide in Adults with Overweight or Obesity and Type 2 Diabetes (REDEFINE 2). N Engl J Med. 2025;393(7):648–659. doi:10.1056/NEJMoa2502082. PMID: 40544432
8. Novo Nordisk A/S. Novo Nordisk files for FDA approval of CagriSema, the first once-weekly combination of GLP-1 and amylin analogues for weight management. Press release, December 2025. https://www.prnewswire.com/news-releases/novo-nordisk-files-for-fda-approval-of-cagrisema-the-first-once-weekly-combination-of-glp1-and-amylin-analogues-for-weight-management-302645862.html
9. Lau J, Bloch P, Schäffer L, et al. Discovery of the once-weekly glucagon-like peptide-1 (GLP-1) analogue semaglutide. J Med Chem. 2015;58(18):7370–7380. DOI: 10.1021/acs.jmedchem.5b00726
10. Wilding JPH, Batterham RL, Calanna S, et al. Once-weekly semaglutide in adults with overweight or obesity (STEP 1). N Engl J Med 2021;384:989–1002. DOI: 10.1056/NEJMoa2032183 · PubMed 33567185
11. Davies M, Færch L, Jeppesen OK, et al. Semaglutide 2.4 mg once a week in adults with overweight or obesity, and type 2 diabetes (STEP 2): a randomised, double-blind, double-dummy, placebo-controlled, phase 3 trial. Lancet 2021;397:971–984. PubMed 33667417
12. Garvey WT, Batterham RL, Bhatta M, et al. Two-year effects of semaglutide in adults with overweight or obesity: the STEP 5 trial. Nat Med 2022;28:2083–2091. DOI: 10.1038/s41591-022-02026-4 · PubMed 36216945
13. Rubino DM, Greenway FL, Khalid U, et al. Effect of weekly subcutaneous semaglutide vs daily liraglutide on body weight in adults with overweight or obesity without diabetes: the STEP 8 randomized clinical trial. JAMA 2022;327(2):138–150. PubMed 35015037
14. Marso SP, Bain SC, Consoli A, et al. Semaglutide and cardiovascular outcomes in patients with type 2 diabetes (SUSTAIN-6). N Engl J Med 2016;375:1834–1844. PubMed 27633186
15. Lincoff AM, Brown-Frandsen K, Colhoun HM, et al. Semaglutide and cardiovascular outcomes in obesity without diabetes (SELECT). N Engl J Med 2023;389:2221–2232. DOI: 10.1056/NEJMoa2307563 · PubMed 37952131
16. Perkovic V, Tuttle KR, Rossing P, et al. Effects of semaglutide on chronic kidney disease in patients with type 2 diabetes (FLOW). N Engl J Med 2024;391(2):109–121. DOI: 10.1056/NEJMoa2403347 · PubMed 38785209
17. Novo Nordisk A/S. CagriSema demonstrated 23% weight loss in an open-label head-to-head REDEFINE 4 trial in people with obesity; the primary endpoint was not achieved. Press release, February 2026. https://www.biospace.com/press-releases/novo-nordisk-a-s-cagrisema-demonstrated-23-weight-loss-in-an-open-label-head-to-head-redefine-4-trial-in-people-with-obesity-the-primary-endpoint-was-not-achieved

This article summarizes published scientific literature for educational purposes only. Semaglutide exists as approved pharmaceutical products (Ozempic, Rybelsus, Wegovy) that are distinct from research-grade material; cagrilintide and CagriSema are investigational compounds not approved for any use. Nothing here constitutes medical advice, describes human use of research materials, or has been evaluated by the FDA.