CagriSema and the REDEFINE 1 Trial: What the Results Actually Mean

CagriSema is a single weekly injection containing two drugs that work on completely different appetite pathways.

The first half is semaglutide 2.4 mg — the same molecule and dose as Wegovy. It mimics GLP-1, a gut hormone released after eating, which slows gastric emptying, increases satiety signalling in the brain, and improves insulin response.

The second half is cagrilintide 2.4 mg, and this is the new part. Cagrilintide is a long-acting amylin analogue. Amylin is a hormone co-secreted with insulin by the pancreas after a meal, and it works through a different set of receptors in the hindbrain than GLP-1 does. Its main jobs are promoting meal-ending satiation and reducing food reward signalling — the pull toward eating for pleasure rather than hunger.

This matters because it is not simply more of the same. Adding more GLP-1 hits a ceiling: side effects climb faster than benefit past a certain dose. Combining two mechanisms that converge on appetite from different directions is how the field is trying to get past that ceiling — the same logic behind [tirzepatide's dual GIP/GLP-1 action](/blog/tirzepatide-vs-semaglutide-which-works-better-2026) and behind [retatrutide's triple-agonist design](/blog/retatrutide-triple-agonist-what-the-triumph-trials-show).

The REDEFINE 1 design was smart about proving this. It did not just compare CagriSema to placebo — it included arms for semaglutide alone *and* cagrilintide alone. That is the only way to show whether the combination genuinely adds up or whether one component is doing all the work.

It was a large, four-arm randomized trial in adults with obesity but without type 2 diabetes.

3,417 adults were enrolled. To qualify, participants needed a BMI of 30 kg/m² or higher, or a BMI of 27 or higher plus at least one weight-related complication such as high blood pressure, sleep apnea, or cardiovascular disease. Everyone received lifestyle intervention alongside their assigned treatment.

Participants were randomly assigned to one of four weekly injections: CagriSema (cagrilintide 2.4 mg plus semaglutide 2.4 mg), semaglutide 2.4 mg alone, cagrilintide 2.4 mg alone, or placebo. The treatment period ran 68 weeks — the same duration as the landmark STEP 1 semaglutide trial, which makes cross-trial comparison at least reasonable in terms of timeline.

One technical detail worth understanding, because it explains why you will see two different numbers reported. Modern obesity trials report results two ways. The treatment policy estimand measures everyone who was randomized regardless of whether they kept taking the drug — closer to real-world results including people who quit. The trial product estimand measures the effect if everyone had stayed on treatment as prescribed — closer to the drug's biological potential. The 22.7% figure is the trial product estimand. The treatment policy figure is somewhat lower.

Neither number is dishonest; they answer different questions. When comparing across drugs, make sure you are comparing the same estimand — a lot of confused online comparisons come from mixing them up.

The threshold data is arguably more useful than the average, because it tells you about your chances rather than about a hypothetical middle person.

Among participants who adhered to CagriSema treatment at 68 weeks: 97.6% lost at least 5% of body weight, 60.2% lost at least 20%, 40.4% lost at least 25%, and 23.1% lost at least 30% (REDEFINE 1, NEJM 2025).

That top figure deserves attention. Nearly one in four participants lost 30% or more of their starting body weight with a weekly injection. For a woman starting at 200 pounds, that is a 60-pound loss. Until very recently, weight loss in that range was achievable only through bariatric surgery. It is not surgical-equivalent across the board — sleeve gastrectomy and gastric bypass still generally produce more, and more durably — but the gap has narrowed substantially.

The 5% figure matters for a different reason. Losing 5% of body weight is the threshold at which meaningful metabolic improvements typically show up: better blood pressure, better lipids, improved insulin sensitivity, reduced sleep apnea severity. That 97.6% of adherent participants cleared it means almost nobody in that group was a complete non-responder.

The trial also reported improvements in cardiometabolic risk factors, including blood pressure. Whether that translates into fewer heart attacks and strokes is a separate question that requires a dedicated outcomes trial — the kind that [semaglutide answered with SELECT](/blog/glp1-heart-health-what-the-select-trial-found). CagriSema does not have that data yet.

Against Wegovy, the comparison is direct and clean. Against Zepbound, it is an estimate — and you should treat it as one.

Versus Wegovy (semaglutide 2.4 mg): REDEFINE 1 tested both in the same trial, in the same population, over the same 68 weeks. CagriSema produced 22.7% versus semaglutide's 16.1%. That is a genuine head-to-head result and the roughly 6.6 percentage point advantage is about as trustworthy as trial evidence gets.

Versus Zepbound (tirzepatide): there has never been a head-to-head trial. The comparison people make is between REDEFINE 1's 22.7% at 68 weeks and SURMOUNT-1's 20.9% at 72 weeks for tirzepatide 15 mg (SURMOUNT-1, NEJM 2022). Those numbers look close, and they are — but they come from different trials, with different participants, different durations, different sites, and potentially different estimands. Cross-trial comparison is genuinely unreliable for differences this small. The honest summary is that CagriSema appears to be in the same performance tier as tirzepatide, not clearly ahead of it.

There is also a more recent comparison point: SURMOUNT-5 directly compared tirzepatide to semaglutide and found tirzepatide superior. So the current picture is a tier of newer dual-mechanism drugs — tirzepatide and CagriSema — sitting above semaglutide alone, with triple agonists like retatrutide potentially above that.

Side effects followed the expected pattern: mostly gastrointestinal, mostly during dose escalation. Our comparison of [Wegovy versus Zepbound](/blog/wegovy-vs-zepbound-which-wins-for-weight-loss-2026) covers what that experience actually feels like day to day.

It is not approved anywhere yet, and there is no confirmed launch date you should plan around.

As of August 2026, CagriSema remains investigational. Novo Nordisk has completed the REDEFINE 1 and REDEFINE 2 trials and has been moving through the regulatory process, but approval timing depends on regulatory review, and companies' projected timelines routinely shift.

A few things worth watching. REDEFINE 2 studied CagriSema in people who have type 2 diabetes — a population that consistently loses less weight on these medications than people without diabetes, so the numbers there are lower by design and should not be compared directly to REDEFINE 1. Manufacturing capacity has been the practical bottleneck for every drug in this class; approval and availability are not the same thing, as anyone who lived through the semaglutide and tirzepatide shortages knows. And pricing and insurance coverage will determine real-world access far more than efficacy will.

What this means practically: CagriSema is not a reason to delay treatment you could start now. The gap between 16% and 22.7% is real, but so is the difference between treatment today and treatment in an uncertain number of years. If a currently available medication is working for you, the pipeline is interesting, not urgent.

If you are following this space, the other names to know are [orforglipron, the first oral small-molecule GLP-1](/blog/orforglipron-first-oral-glp1-pill-explained), and [survodutide, a glucagon/GLP-1 dual agonist](/blog/survodutide-glucagon-glp1-dual-agonist-what-trials-show).

Yes, and the distinction may matter for who responds and how the experience feels.

Amylin and GLP-1 both reduce food intake, but they act through separate receptor systems and separate brain circuits. GLP-1 receptor agonists work heavily on hunger and on gastric emptying — you eat less because you are less hungry and because food sits in your stomach longer. Amylin analogues act on the area postrema and other hindbrain regions to promote satiation, the signal that ends a meal, and there is evidence they reduce food reward — the hedonic pull toward eating that is not about hunger at all.

That second effect is interesting for anyone who has described their experience as "I'm not hungry, but I still want to eat." Whether cagrilintide meaningfully changes that in practice is not something a weight number can tell you, and the trial did not measure it directly in a way that answers the question. But the mechanism is a plausible reason some people might respond to the combination who did not respond well to a GLP-1 alone — and it sits alongside what many people describe as the quieting of [food noise on a GLP-1](/blog/food-noise-on-glp1-what-it-is-and-why-it-quiets).

There is also a preservation-of-lean-mass question that the field is watching closely across all of these drugs. Rapid weight loss costs muscle, and in midlife women who are already losing muscle to falling estrogen, that matters a great deal — see our guide to [the sarcopenia double risk](/blog/glp1-menopause-muscle-loss-the-sarcopenia-double-risk). Body composition data will be an important part of judging any of these newer agents, and it deserves more attention than the headline percentage.