Cagrilintide vs Semaglutide: Amylin vs GLP-1 Research Comparison

Cagrilintide and semaglutide act on complementary satiety pathways: cagrilintide is a long-acting amylin analog; semaglutide is a GLP-1 receptor agonist. Their combination (CagriSema) is among the most-discussed obesity-research programs of the decade. This comparison summarises the published literature relevant to laboratory research.

At-a-glance comparison

| Attribute | Cagrilintide | Semaglutide | |---|---|---| | Class | Long-acting amylin analog | GLP-1 receptor agonist | | Receptor | Amylin (AMY1/2/3), calcitonin | GLP-1 | | Mechanism | Slows gastric emptying, central satiety | Insulin secretion, slows gastric emptying, central satiety | | Half-life | ~7 days (weekly dosing) | ~7 days (weekly dosing) | | Monotherapy weight loss (published) | ~10% at 26 weeks (Phase 2) | ~15% at 68 weeks (STEP trials) | | Combination (CagriSema) | ~17-22% in published Phase 2 | Same |

Mechanism — two satiety axes

Amylin and GLP-1 are both endogenous gut/pancreatic hormones released with meals, but they signal through different receptors and brain regions. The published rationale for combining them is additive satiety with non-overlapping receptor pharmacology — neither saturates the other's pathway, so combination effects exceed either alone in clinical research.

Published research highlights

• Cagrilintide Phase 2 (Lancet, 2021) reported dose-dependent weight loss up to ~10% at 26 weeks with weekly dosing.
• Semaglutide STEP trials (NEJM, 2021+) reported ~15% mean weight reduction at 68 weeks at 2.4 mg weekly.
• CagriSema Phase 2 (REDEFINE program) reported combined weight loss in the high teens to low 20s percentage range, exceeding either monotherapy.

Pharmacokinetics — both built for weekly dosing

Both peptides use fatty-acid acylation for albumin binding to achieve ~7-day half-lives suitable for once-weekly subcutaneous research dosing. This parallel pharmacokinetic profile is part of why fixed-ratio co-formulation became feasible.

Side-effect spectrum in published research

Both classes share GI-dominant side effects (nausea, vomiting, diarrhea, constipation) driven by gastric-emptying delay. Published combination data suggests GI tolerability is broadly similar to semaglutide monotherapy rather than additive — a key finding supporting clinical development.

Frequently asked research questions

Why combine them if they overlap on gastric emptying? Central satiety mechanisms differ. Amylin acts on area postrema and hindbrain; GLP-1 acts on hypothalamic and brainstem GLP-1R populations. The combination amplifies satiety beyond gastric effects.

Is cagrilintide just a better pramlintide? Pramlintide (the first amylin analog) requires three-times-daily dosing due to short half-life. Cagrilintide's acylation extends half-life to weekly — a major operational advance.

Where does retatrutide fit? Retatrutide is a triple agonist (GLP-1/GIP/glucagon) — a different research strategy than CagriSema's dual-hormone-class approach.

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