CagriSema: Two Molecules That Landed Where One Already Was

CagriSema combines two drugs, cagrilintide and semaglutide, and produced 20.4% weight loss in REDEFINE-1. Tirzepatide 15 mg alone produced 20.9%. Two molecules, two mechanisms and the largest trial in the class landed where one molecule already sat.

That is the whole CagriSema story, and it explains the reception the readout got. The combination pairs cagrilintide, a long-acting amylin analogue, with semaglutide, a GLP-1 receptor agonist — two of the weight loss and metabolic peptides working through independent pathways. The theory was that stacking them would push weight loss past what either could achieve alone, and past what a GLP-1-based competitor could reach.

One correction before anything else: the published primary figure is 20.4%, not the 22.7% that circulates widely.

Does CagriSema beat tirzepatide?

No published evidence supports a superiority claim in either direction. CagriSema, a two-drug regimen at full doses of both components, produced 20.4% weight loss in 3,417 adults over 68 weeks in REDEFINE-1; tirzepatide 15 mg alone produced 20.9% in 2,539 adults over 72 weeks in SURMOUNT-1. Placebo-adjusted, the two sit within half a percentage point of each other — 17.3 points against 17.8. No head-to-head trial exists.

Cross-trial comparison is not head-to-head, and populations and estimands differ — but the arithmetic is what drove the reception.

A two-component regimen, at full doses of both, in the larger trial, produced essentially the same result as a single molecule.

Two caveats in CagriSema's favour are worth stating fairly. REDEFINE-1 is the larger and more rigorous trial at 3,417 participants with monotherapy control arms, which SURMOUNT-1 did not have. And the tolerability comparison may differ from the efficacy one — gastrointestinal adverse events ran 79.6% in REDEFINE-1, and without a published discontinuation figure we cannot compare that to tirzepatide's 6.2%.

We are reporting the numbers and being careful with the framing. We could not verify the market-reaction narrative — financial press was not accessible to us — so we are not characterising how investors responded. The comparison above is the substantive point, and it stands on its own.

Is CagriSema's weight loss 20.4% or 22.7%?

CagriSema's published primary result is 20.4%, the treatment-policy estimand reported in the NEJM abstract for REDEFINE-1. The 22.7% figure that circulates widely we could not verify from the publication, and it should not be presented as the headline. The difference matters for the comparison this compound is judged by: 20.4% against tirzepatide's 20.9% is a dead heat; 22.7% would have told a different story.

This is not a pedantic distinction. Every secondary claim built on the higher number — that CagriSema is the most effective obesity drug tested, that the combination proved its rationale, that it clears tirzepatide — depends on a figure we could not source from the NEJM publication. Anyone quoting 22.7% should locate it in the paper before repeating it.

What did REDEFINE-1 and REDEFINE-2 actually report?

REDEFINE-1 reported −20.4% versus −3.0% on placebo over 68 weeks in 3,417 adults, a difference of 17.3 percentage points (95% CI −18.1 to −16.6), P<0.001, with gastrointestinal adverse events in 79.6% against 39.9%. REDEFINE-2, in 1,206 adults with type 2 diabetes, reported −13.7% versus −3.4%, a difference of 10.4 points, P<0.001. Both were published in the NEJM on 14 August 2025.

REDEFINE-1 — Garvey et al., "Coadministered Cagrilintide and Semaglutide in Adults with Overweight or Obesity," NEJM, 14 August 2025 (PMID 40544433). NCT05567796, n=3,417, 68 weeks. The design is unusually informative because it included monotherapy arms: cagrilintide-semaglutide 2,108; semaglutide alone 302; cagrilintide alone 302; placebo 705.

Gastrointestinal events were "mainly transient and mild-to-moderate." The discontinuation rate is not reported in the abstract and we are not quoting one.

REDEFINE-2 — Davies et al., NEJM, 14 August 2025 (PMID 40544432). NCT05394519, n=1,206, adults with overweight or obesity and type 2 diabetes, 68 weeks. The result was −13.7% versus −3.4%, a difference of 10.4 percentage points (95% CI −11.2 to −9.5), P<0.001. HbA1c reached 6.5% or below in 73.5% versus 15.9%, and gastrointestinal adverse events ran 72.5% versus 34.4%. The drop from 20.4% to 13.7% in the diabetes population is expected — every drug in this class loses roughly a third of its weight effect in people with type 2 diabetes — but it is worth stating, because the 20.4% headline is often quoted without the population attached.

REIMAGINE-3 — Rosenstock et al., The Lancet, 4 July 2026 (PMID 42251856), tested cagrilintide-semaglutide as an add-on to basal insulin in type 2 diabetes.

What is CagriSema, and why combine amylin with GLP-1?

CagriSema pairs cagrilintide, a long-acting amylin analogue also described as a dual amylin/calcitonin receptor agonist, with semaglutide, a GLP-1 receptor agonist, at 2.4 mg and 2.4 mg once weekly — 1:1 by mass. Cagrilintide is CAS 1415456-99-3, C₁₉₄H₃₁₂N₅₄O₅₉S₂, MW 4,409.0. The rationale is pathway independence: amylin is a pancreatic hormone co-secreted with insulin that promotes satiety through a route distinct from GLP-1.

The mechanistic rationale is sound. Combining amylin with GLP-1 targets appetite through two independent routes rather than pushing harder on one, which is a different bet from a single molecule engineered to hit two receptors at once.

PubChem also carries acetate-salt entries for cagrilintide separately from the free base — which matters for anyone weighing out grey-market material, because the two records describe different masses of the same active peptide. See TFA versus acetate versus amidate salt forms.

What could not be established about CagriSema?

Four things about CagriSema could not be established from the published record. How it is supplied is the first — ten CagriSema papers were searched and none describes the formulation or delivery device, so we are not asserting it is a single co-formulated pen. The others are REDEFINE-1's monotherapy arm results (figures of 11.5% and 14.9% circulate but are not in the NEJM abstract), whether Novo Nordisk has filed anywhere, and the market-reaction narrative.

Formulation. The REDEFINE-1 paper's title uses the word "Coadministered," while REDEFINE-2 and REIMAGINE-3 use the hyphenated name "cagrilintide-semaglutide." That is suggestive in both directions and conclusive in neither. Nobody should assert a delivery format without a source.

The monotherapy arms. These are the most interesting numbers in the trial, because they would show how much the combination adds over each component alone. Figures circulate — commonly cagrilintide 11.5% and semaglutide 14.9% — but those are not in the NEJM abstract and we could not verify them. Anyone using them should locate the source in the full paper.

Filing status. Whether Novo Nordisk has filed, and any decision date, we could not verify — the company's newsroom pages were not retrievable — so we are not asserting either way.

Market reaction. Financial press was not accessible to us, so we do not characterise how the readout was received by investors.

How does CagriSema rank against the rest of the class?

CagriSema's 20.4% places it third in this class on both raw and placebo-adjusted weight loss, behind retatrutide's 24.2% at 12 mg — which is phase 2 data, not phase 3 — and marginally behind tirzepatide's 20.9%. It sits ahead of mazdutide's 16.65%, semaglutide's 14.9% and survodutide's 13.0%. In type 2 diabetes, REDEFINE-2's 13.7% drops it near the bottom of the same table. All of those are cross-trial comparisons, not head-to-head results.

Populations, durations, estimands and placebo responses all differ across these trials.

CagriSema and tirzepatide sit within half a percentage point of each other on both raw and placebo-adjusted measures. Only a head-to-head trial would separate them, and none exists.

For context on what else is now available: orforglipron (Foundayo), an oral GLP-1, was FDA-approved on 1 April 2026 for obesity. See oral GLP-1: orforglipron versus peptides.

Which CagriSema claims hold up?

The 20.4% weight-loss figure holds; the 22.7% figure is not the published number. The claim that CagriSema beats tirzepatide has no supporting evidence — cross-trial, it is 20.4% against 20.9%. Three widely repeated claims are simply unverified: that it is supplied as a single co-formulated pen, that the monotherapy arms lost 11.5% and 14.9%, and that a regulatory filing exists. It is approved nowhere.

Is CagriSema approved, and can either half be compounded?

CagriSema is not approved. FDA's drug application database returns no record for cagrilintide, and CagriSema is absent from FDA's novel approvals lists for 2025 (46 drugs) and 2026 (30 drugs, current through 5 August 2026). Neither half can now be compounded: cagrilintide has never been approved, so it has never been in shortage, and FDA's shortage database lists Semaglutide Injection as "Resolved", which ends the shortage-based route.

A peer-reviewed statement from BMJ Open in 2025 puts the status plainly: "CagriSema is currently not approved, but several phase III trials are ongoing." Whether Novo Nordisk has filed, and any decision date, we could not verify.

It does not appear on FDA's compounding lists. We enumerated both tables on the page current 22 April 2026 — no GLP-1, GIP, glucagon or amylin agonist is on either. That absence carries no permission. As the peer-reviewed summary puts it, "with the shortage of innovator semaglutide or tirzepatide products resolved, compounding pharmacies can only legally sell unique products."

FDA's specific warnings on this class apply to anyone buying either component: salt forms "are different active ingredients than are used in the approved drugs," and the agency has "warned companies that have illegally sold unapproved drugs... falsely labeled 'for research purposes' or 'not for human consumption.'" See our FDA peptide regulation timeline.

On WADA, neither cagrilintide nor semaglutide is named on the 2026 Prohibited List, and no GLP-1 or amylin class entry exists. Semaglutide is approved and therefore outside the S0 catch-all. Cagrilintide is approved nowhere, which on S0's plain text — "no current approval by any governmental regulatory health authority for human therapeutic use" — would capture it. That is our reading rather than a published ruling.

What does a 94% overage mean for a component dosed at 2.4 mg?

Cagrilintide averages 99.62% purity across 254 independent tests on the Peptigrity Purity Index (verified August 2026), from four labs — ILS, Kovera, Janoshik and Freedom Diagnostics — across 224 shops selling. One June 2026 sample labelled 10 mg tested at 19.4 mg: a 94% overage, the most extreme quantity anomaly on this platform, where most other tests run within ±3% to 17%. Dosing by label from that batch means taking roughly double.

A 94% overage is not a fill-accuracy problem in the ordinary sense; it is a vial containing about twice the labelled dose of a drug titrated to 2.4 mg. Anyone dosing by label from that batch would have taken roughly double what they intended, of a compound whose trial produced gastrointestinal adverse events in 79.6% of participants at the correct dose.

Cagrilintide price data shows 47 shops in stock, median $11.90/mg, lowest $3.00/mg on a 10 mg vial (verified 10 August 2026), across 55 compared offers with vial prices from $30.00 to $263.99. The page records 126 vendors known to sell it, 53 with active listings and 73 evidenced by recent lab testing. Those figures exclude shipping, taxes and customs, coupon codes, bulk tiers, multi-vial kits and account-gated pricing. They sit within 11,852 independent lab tests across 530 tracked shops (verified August 2026).

Because a vial can contain nearly twice its label, work from the assayed quantity where you have one: use the semaglutide calculator alongside the reconstitution calculator. Compare vendors on the cagrilintide compound page, and see our cagrilintide science article for the amylin component on its own.

The trial that would settle this

A head-to-head trial against tirzepatide 15 mg is the study that would settle CagriSema's central question, because 20.4% against 20.9% cross-trial resolves nothing. The second requirement is cheaper: publish REDEFINE-1's monotherapy arms clearly. The trial spent 604 participants — 302 on cagrilintide alone and 302 on semaglutide alone — specifically to measure what the combination adds, and that number is not in the abstract.

The second row is the one that would answer the scientific question, and it costs nothing — the data already exists.

Frequently Asked Questions

How much weight did CagriSema produce?

REDEFINE-1 reported −20.4% over 68 weeks in 3,417 adults, versus −3.0% on placebo, a difference of 17.3 percentage points, P<0.001. In adults with type 2 diabetes, REDEFINE-2 reported −13.7% versus −3.4%.

Isn't the figure 22.7%?

The published primary in the NEJM abstract is 20.4%, the treatment-policy estimand. We could not verify a 22.7% figure from the publication and are not presenting it as the headline. Anyone quoting it should locate it in the full paper first.

Does CagriSema beat tirzepatide?

There is no head-to-head trial. Cross-trial, CagriSema's 20.4% and tirzepatide 15 mg's 20.9% are within half a percentage point, and their placebo-adjusted effects are within half a point too. Nothing in the published record supports a superiority claim in either direction.

Is CagriSema approved?

No. It does not appear in FDA's drug application database or on FDA's novel approvals lists for 2025 or 2026. We could not determine whether a filing has been made. A 2025 BMJ Open statement puts it as "currently not approved, but several phase III trials are ongoing."

How is it supplied?

We could not establish this. The REDEFINE-1 paper title uses "coadministered," while later papers use the hyphenated drug name. No paper we reviewed describes the formulation or delivery device, so we are not asserting that it is a single pen.

What's the main quality risk on the research market?

Fill quantity. One cagrilintide sample on this platform tested at 19.4 mg against a 10 mg label — a 94% overage, on a component dosed at 2.4 mg, in a regimen that produced gastrointestinal adverse events in nearly 80% of trial participants at the correct dose.

What CagriSema proves and what it does not

CagriSema proves that combining amylin and GLP-1 produces 20.4% weight loss over 68 weeks in 3,417 people, with 17.3 points of separation from placebo — real medicine, in the largest trial in this class, and one better designed than most. What it does not prove is that two molecules do anything a single molecule cannot: tirzepatide alone reached 20.9%. The monotherapy arms that would show the combination's internal contribution are unpublished.

Nobody should read this article as saying 20% weight loss is unimpressive. REDEFINE-1 is a better-designed trial than most in this field, precisely because it kept monotherapy arms to measure what the combination actually contributes. The problem is that the measurement was made and not reported.

For anyone buying cagrilintide on the research market, none of that is the binding issue. It has never been approved anywhere, has no compounding pathway and never has had one, and one vial tested on this platform contained nearly twice what its label said.

Browse the weight loss and metabolic peptides category, or our complete peptide guide with 118 compounds (verified August 2026). For per-injection volume, use the semaglutide calculator alongside the reconstitution calculator. Compare shops through independent lab tests and community-verified shop reviews.

This article is for educational and informational purposes only and does not constitute medical advice. Peptides discussed may be investigational compounds not approved by the FDA (or equivalent regulators in your jurisdiction) for human use. Always consult a qualified healthcare provider before using any peptide or research compound. Peptigrity is an independent review platform and does not sell, endorse, or recommend specific products or vendors.