Cagrilintide: The Amylin Analogue Behind CagriSema — What the Evidence Shows

Cagrilintide is a long-acting synthetic analogue of amylin — the pancreatic hormone co-secreted with insulin that curbs appetite and slows gastric emptying through a pathway separate from GLP-1. It is being developed by Novo Nordisk, and as of 2026 it is investigational and not FDA-approved in any form. Most people encounter the name as the amylin half of CagriSema (cagrilintide 2.4 mg + semaglutide 2.4 mg), but cagrilintide also has its own monotherapy evidence: the phase 2 dose-finding trial (Lau 2021 Lancet^[1]) showed dose-dependent weight loss reaching about −10.8% at 26 weeks on the top 4.5 mg dose — more than placebo (−3.0%) and more than the active comparator liraglutide 3.0 mg (−9.0%). This article covers what cagrilintide actually is, the trial data behind it, where it sits in development, and what it means for patients today.

The honest summary

• Cagrilintide is an amylin analogue, not a GLP-1 drug. Amylin is co-secreted with insulin from pancreatic beta cells; it suppresses appetite via the area postrema, slows gastric emptying, and promotes satiety through receptors that are distinct from the GLP-1 receptor. Cagrilintide is engineered for once-weekly dosing.
• It is investigational and not approved. As of 2026, cagrilintide is not FDA-approved as a standalone weight-loss drug. The most advanced program it belongs to is the fixed-dose combination CagriSema (with semaglutide), still under regulatory review.
• Monotherapy phase 2: about -10.8% body weight at 26 weeks on the 4.5 mg dose vs -3.0% on placebo and -9.0% on liraglutide 3.0 mg, with a clean dose response across 0.3 to 4.5 mg (Lau 2021 Lancet^[1]).
• The combination rationale: amylin agonism and GLP-1 agonism work through complementary, non-overlapping pathways. Stacking them is the entire bet behind CagriSema and the phase 1b combo data that preceded it (Enebo 2021 Lancet^[2]).
• Magnitude context: cagrilintide monotherapy's phase 2 number sits below the approved injectables — semaglutide 2.4 mg reached -14.9% in STEP-1 (Wilding 2021^[3]) and tirzepatide reached -20.9% in SURMOUNT-1 (Jastreboff 2022^[4]) — but those were longer 68- to 72-week trials, and cagrilintide's role is increasingly as a combination partner rather than a solo agent.

What cagrilintide actually is, pharmacologically

Amylin (also called islet amyloid polypeptide) is a 37-amino-acid peptide hormone released alongside insulin from pancreatic beta cells after a meal. Its physiological job is to help regulate post-meal glucose and appetite: it slows gastric emptying, suppresses inappropriate glucagon secretion, and signals satiety in the hindbrain — specifically at amylin receptors in the area postrema and the surrounding dorsal vagal complex. Native human amylin is unsuitable as a drug because it aggregates and has a very short half-life. The first amylin-based medicine, pramlintide (Symlin), solved the aggregation problem but had to be injected at every meal.

Cagrilintide is a next-generation answer to that limitation: a long-acting amylin analogue engineered for once-weekly subcutaneous dosing. It activates amylin (calcitonin-family) receptors with high affinity, reproducing amylin's appetite-suppressing and gastric-slowing effects while lasting long enough for weekly administration. Crucially, the receptor it targets is different from the GLP-1 receptor that semaglutide, liraglutide, and tirzepatide's GLP-1 component act on. That separation is what makes amylin agonism a complementary lever rather than a redundant one.

The monotherapy evidence: Lau 2021 Lancet phase 2

The pivotal standalone evidence for cagrilintide is Lau 2021^[1], a multicentre, randomised, double-blind, placebo-controlled and active-controlled phase 2 dose-finding trial published in The Lancet. It enrolled adults with overweight or obesity and tested once-weekly cagrilintide across a range of doses (0.3, 0.6, 1.2, 2.4, and 4.5 mg) against both placebo and an active comparator, the approved GLP-1 drug liraglutide 3.0 mg, over 26 weeks. All arms received the same lifestyle-intervention backdrop.

The result was a clean dose-response signal: weight loss increased with dose, and the top 4.5 mg arm produced roughly −10.8% body weight at 26 weeks, compared with about −3.0% on placebo and −9.0% on liraglutide 3.0 mg. In other words, the highest cagrilintide dose outperformed both placebo and an established once-daily GLP-1 standard-of-care over the same period. The safety profile was consistent with what amylin and incretin-based drugs produce: the most common adverse events were gastrointestinal (nausea, vomiting, decreased appetite, constipation), dose-related, and concentrated in the early titration weeks. No unexpected safety signals were reported.

Two caveats keep this in honest perspective. First, 26 weeks is shorter than the 68- to 72-week pivotal trials that defined the approved obesity injectables, so the absolute magnitude is not directly comparable to STEP or SURMOUNT numbers. Second, this was a phase 2 dose-finding study — its job was to establish the dose-response curve and tolerable top dose, not to serve as a registration trial. That top dose (and the lessons about combining amylin with GLP-1) fed directly into the CagriSema program rather than into a standalone cagrilintide filing.

From monotherapy to combination: the CagriSema story

Before CagriSema's phase 3 readouts, Enebo 2021^[2] reported a phase 1b trial in The Lancet testing concomitant administration of cagrilintide with semaglutide 2.4 mg. It established that the two could be given together safely and that the combination was tolerable, clearing the way for the fixed-dose combination. The pharmacological premise — amylin agonism plus GLP-1 agonism through complementary pathways — is exactly why Novo pursued the combination rather than pushing cagrilintide alone to phase 3.

The full phase 3 magnitude for the combination lives in the REDEFINE program: REDEFINE 1 (Garvey 2025 NEJM^[5]) in adults with overweight or obesity without diabetes, and REDEFINE 2 (Davies 2025 NEJM^[6]) in adults with type 2 diabetes. Rather than re-cover those numbers here, see the dedicated CagriSema REDEFINE trial results article. The relevant point for understanding cagrilintide-the-molecule is that its strategic role has shifted from a candidate solo drug to the amylin engine inside a combination product.

Magnitude: cagrilintide vs the approved injectables

Where cagrilintide sits in development

As of 2026, there is no FDA-approved standalone cagrilintide product. Its furthest-advanced path to patients is the CagriSema fixed-dose combination, which has completed its REDEFINE phase 3 obesity and diabetes trials and is under regulatory review. Whether cagrilintide is ever marketed as a monotherapy is uncertain — the commercial and clinical momentum is behind the combination, where the amylin and GLP-1 mechanisms reinforce each other. Cagrilintide also sits inside a broader Novo amylin strategy that includes the unimolecular GLP-1 + amylin co-agonist amycretin and a wider field of next-generation candidates tracked in the GLP-1 pipeline overview.

What this means for patients today

Cagrilintide is not prescribable on its own, is not available from any legitimate compounding or research-peptide source, and should not be sought outside of a clinical trial. Anything advertised as “cagrilintide” in an unregulated peptide marketplace carries the usual risks of unverified identity, purity, and dose, and there is no approved standalone product to compare it against. If you are interested in amylin-based therapy, the realistic near-term route is the CagriSema combination once it is approved and prescribed by a clinician — not cagrilintide as a solo agent.

For decisions you can act on now, the relevant drugs are the approved ones: Wegovy (semaglutide 2.4 mg, STEP-1^[3]) and Zepbound (tirzepatide, SURMOUNT-1^[4]). If you and your clinician are weighing options, the right conversation is about an approved medication that fits your health profile — with cagrilintide and CagriSema as something to revisit if and when the combination reaches the market.