CagriSema

CagriSema is one of the most heavily studied combination products in the pipeline of new obesity drugs. It’s also a good example of why “strong trial data” and “proven, approved, and better than the alternatives” are not the same thing. It’s a once-weekly shot that packs two peptides into a single product: cagrilintide, a long-acting amylin analog (a lab-made copy of a natural fullness hormone), plus semaglutide 2.4 mg, the GLP-1 drug already sold as Wegovy. It has been put through large, carefully run trials published in top medical journals — but it isn’t approved anywhere, it fell short of its own company’s expectations, and a head-to-head trial against tirzepatide failed to show it was even as good (let alone better). This is not medical advice, and this profile does not cover dosing.

What it is

CagriSema combines two peptides that both turn down appetite, but through partly different routes. Semaglutide is a GLP-1 (glucagon-like peptide-1, a gut hormone) receptor agonist — meaning it switches on the same receptors that hormone uses. It works along the gut-brain axis to make you feel full sooner, slow how fast the stomach empties, prompt the right amount of insulin only when blood sugar is up, and lower glucagon (a hormone that raises blood sugar). Cagrilintide is a copy of amylin, a hormone from the pancreas that also signals fullness. It switches on amylin and calcitonin receptors in two appetite-control areas of the brain (the brainstem and the hypothalamus) to cut food intake — and it does this largely through a separate pathway from GLP-1.

The idea is simple: nudge two different fullness circuits at the same time and you should get more weight loss than either drug on its own. The big Phase 3 trial (a large, late-stage human study) was built to test exactly that, with separate groups for the combination, semaglutide alone, cagrilintide alone, and a placebo (a dummy treatment).

The claims

In its legitimate development, CagriSema is being studied for long-term weight management in adults who have obesity, or who are overweight plus have at least one weight-related health problem. It’s also being studied for combined weight loss and blood-sugar control in people with type 2 diabetes. Novo Nordisk has said that, if it’s approved, it would be the first once-weekly shot to combine a GLP-1 drug and an amylin analog for weight management.

The big promise floating around CagriSema was that stacking two fullness mechanisms would push weight loss past what GLP-1 drugs alone can do — and past tirzepatide too. The trial data complicate both halves of that claim.

What the evidence actually shows

The human dataset is large, and for the two published trials, high quality.

• Obesity without diabetes (REDEFINE 1; NCT05567796): A Phase 3 trial of 3,417 adults split at random into CagriSema, semaglutide alone, cagrilintide alone, or placebo over 68 weeks. CagriSema produced about 22.7% mean weight loss (trial-product estimand — an analysis that estimates the effect if people stayed on treatment as planned); using the treatment-policy estimand (which counts everyone regardless of whether they stuck with it) it was −20.4% versus −3.0% on placebo. More than half of CagriSema patients lost at least 20% of their weight, and over 90% lost at least 5%. Two honest caveats: the 22.7% result fell short of the roughly 25% management had hinted at in the December 2024 first look, and it was treated as a letdown. Published by Garvey and colleagues in NEJM (PMID 40544433).
• Type 2 diabetes (REDEFINE 2; NCT05394519): A Phase 3 trial of 1,206 adults. CagriSema produced about 13.7% weight loss versus 3.4% on placebo (treatment-policy estimand; the estimated gap between treatments was about 10.4 percentage points), and 73.5% of CagriSema patients reached an HbA1c of 6.5% or lower versus 15.9% on placebo (HbA1c is a blood test that shows your average blood sugar over the past few months), with an HbA1c drop in the range of roughly 1.8 to 1.9 percentage points. Published by Davies and colleagues in NEJM (PMID 40544432).
• Head-to-head against tirzepatide (REDEFINE 4): An open-label (everyone knew which drug they were getting) Phase 3 trial of 809 adults over 84 weeks, reported in February 2026 as a company top-line result (early headline numbers, not yet a full published paper). CagriSema produced 23.0% weight loss versus 25.5% for tirzepatide 15 mg (efficacy estimand; 20.2% versus 23.6% on the treatment-regimen estimand). Crucially, the trial did NOT meet its primary endpoint of non-inferiority to tirzepatide — that is, it failed to show it was at least as good. This is company top-line data; a peer-reviewed publication is not yet confirmed.
• Cardiovascular outcomes (REDEFINE 3): An ongoing, event-driven Phase 3 trial of roughly 7,000 adults who already have heart or blood-vessel disease (with or without type 2 diabetes). There are no heart-outcome results yet.
• Body composition (REDEFINE 1 DXA subset, n = 252): In this planned-in-advance subgroup (measured with DXA, a body-scan that separates fat from muscle and bone), about two-thirds of the weight lost was fat (66.9%) and about one-third was lean soft tissue (33.1%) — a relatively good ratio, but some muscle loss does come along with large weight loss. Reported at ObesityWeek 2025.

The strongest evidence — REDEFINE 1 and REDEFINE 2 — is large, randomized, and peer-reviewed (checked by independent experts before publishing). The tirzepatide comparison and the body-composition figures are still just company top-line numbers and conference presentations, not yet full published papers, and whether it helps the heart long-term stays an open question until REDEFINE 3 reports.

Legal and regulatory status

CagriSema is not approved by the FDA or any other regulator as of mid-2026; it’s still investigational (in testing, not yet cleared for sale). Novo Nordisk submitted a New Drug Application to the FDA on 18 December 2025 for long-term weight management, with review expected during 2026.

For athletes, the picture is often reported wrong. GLP-1 drugs, including semaglutide, are not banned in sport for 2026 — they sit on WADA’s Monitoring Program (semaglutide since 2024; for 2026 the program was adjusted to also keep an eye on markers of tirzepatide). Being on the Monitoring Program is not a rule violation and does not require a Therapeutic Use Exemption (special medical permission). The claim going around online that GLP-1s were moved into a banned category (S4, “Hormone and Metabolic Modulators”) in January 2026 is false, according to USADA’s GLP-1 advisory and WADA’s 2026 publications. WADA is looking at a possible future ban, but none is in effect right now. (For context, growth factors such as IGF-1 and MGF are banned separately under S2 — a different category from the incretin and amylin peptides here.)

Safety

The main side effects hit the gut. In REDEFINE 1, gastrointestinal (stomach and gut) side effects showed up in 79.6% of CagriSema patients versus 39.9% on placebo, including nausea, constipation, and vomiting. Most were mild to moderate, were tied to the dose being slowly raised, and eased off over time across REDEFINE 1 and 4. The share of people quitting because of side effects was in the low single digits, only a little above placebo.

A REDEFINE 1 analysis in Hypertension (PMID 41328546) found a bigger drop in blood pressure with CagriSema than placebo (systolic — the top number — −10.9 versus −2.8 mm Hg; diastolic — the bottom number — −5.4 versus −1.7 mm Hg). But this looks at a risk factor, not at actual heart events; those answers wait on REDEFINE 3. And as with any large weight loss, some muscle loss comes along with the fat loss, though the fat-to-muscle ratio in the DXA scan subgroup was relatively good.

A few warnings are borrowed from the GLP-1 drug class as a whole rather than coming from CagriSema’s own trials: a thyroid C-cell tumor warning based on rodent studies (not for people with a personal or family history of medullary thyroid carcinoma, a type of thyroid cancer, or MEN2, an inherited tumor syndrome), pancreatitis (inflammation of the pancreas), gallbladder problems, and a new, still-being-studied safety signal for NAION (non-arteritic anterior ischemic optic neuropathy, a kind of sudden vision loss from reduced blood flow to the optic nerve). Treat these as class-wide concerns, and in the NAION case, still under investigation.

Bottom line

CagriSema has genuinely strong randomized human evidence for weight loss in two large, peer-reviewed Phase 3 trials — one in obesity, one in type 2 diabetes — which is more than almost any compound talked about on peptide forums can say. But the story is more cautious than the early hype suggested: it came in under its own company’s headline expectations, it failed to prove it was at least as good as tirzepatide in a direct head-to-head, it’s not approved anywhere, and the heart-outcomes trial hasn’t reported. How well it works is well established by high-quality trials; where it fits next to existing drugs, what it does over the long haul, and its regulatory future are all still unsettled.

Evidence grade: 9/10 · Strong.

Sources

• Garvey WT et al. CagriSema in obesity (REDEFINE 1). NEJM, 2025 (PMID 40544433)
• Davies MJ et al. CagriSema in type 2 diabetes (REDEFINE 2). NEJM, 2025 (PMID 40544432; NCT05394519)
• ClinicalTrials.gov — REDEFINE 1 (NCT05567796)
• Novo Nordisk: REDEFINE 1 22.7% weight reduction, NEJM publication (press release)
• Novo Nordisk: FDA NDA filing for CagriSema, December 2025 (press release)
• Novo Nordisk / GlobeNewswire: REDEFINE 4 top-line, non-inferiority not met (23 Feb 2026)
• REDEFINE 3 cardiovascular outcomes trial — UK HRA summary
• REDEFINE 1 body composition (DXA), ObesityWeek 2025 (Ravussin et al.)
• CagriSema blood pressure analysis (REDEFINE 1). Hypertension (PMID 41328546)
• USADA: Weight Loss Drugs — what athletes need to know about GLP-1s
• WADA publishes 2026 Prohibited List