Cagrilintide: What the Evidence Actually Shows

Start with the finding most cagrilintide marketing skips rather than the mechanism story marketing usually leads with: in Novo Nordisk's own Phase 3 trial, cagrilintide by itself produced less weight loss than semaglutide by itself. In REDEFINE-1 — the 3,417-person trial behind cagrilintide's current FDA filing — the cagrilintide-alone arm lost 11.8% of body weight at week 68, while the semaglutide-alone arm, running in the very same trial, lost 16.1%¹. Cagrilintide is real, its trial program is large and well-published, and none of that changes this specific result: on its own, it was the weaker of the two drugs it was tested against, in the trial that put it up for FDA review.

That result matters for a specific, practical reason this article returns to at the end: a compounding pharmacy could theoretically prepare cagrilintide alone, but never the CagriSema combination that reached 22.7% in that same trial¹ — the fixed-dose combination is Novo Nordisk's patented, filed product, not a compoundable formula. Cagrilintide's own solo number is the one that matters for that comparison, not the combination's.

What cagrilintide is, and its proposed mechanism

Cagrilintide is a long-acting synthetic analog of amylin, a hormone the pancreas co-secretes with insulin that signals satiety to the brain. It binds three amylin receptor subtypes (AMY1R, AMY2R, AMY3R) plus the calcitonin receptor, and its long duration of action — supporting once-weekly dosing — comes from fatty-acid acylation, the same chemistry Novo Nordisk uses to extend semaglutide's half-life¹. Structurally and mechanistically it has essentially nothing to do with GLP-1 receptor agonists like semaglutide or tirzepatide: amylin and GLP-1 are different hormones acting through different receptors, which is the pharmacological rationale for combining cagrilintide with a GLP-1 drug in the first place — two independent appetite-regulation pathways engaged at once, rather than pushing harder on one¹.

That rationale predates REDEFINE-1 by several years. An earlier Phase 1b safety and pharmacokinetics trial tested cagrilintide co-administered with semaglutide 2.4 mg for the first time: at 20 weeks, cagrilintide 2.4 mg plus semaglutide produced 17.1% mean weight reduction against 9.8% for pooled placebo — a small, short trial, but an early signal of the combination effect REDEFINE-1 later confirmed at scale⁵. Before that combination was tested at all, a Phase 2 dose-finding trial established that cagrilintide has real, dose-responsive efficacy as a monotherapy in its own right: across the tested doses (0.3-4.5 mg), mean weight reduction at week 26 ranged 6.0%-10.8%, all significantly greater than pooled placebo's 3.0%⁴. Cagrilintide alone works, in the sense that it beats placebo by a wide, statistically clean margin. The open question REDEFINE-1 was actually built to answer wasn't whether cagrilintide works — it was how it stacks up against semaglutide, alone and combined.

What the monotherapy data actually shows

REDEFINE-1 randomized 3,417 adults with overweight or obesity (without diabetes) across four arms: CagriSema (cagrilintide 2.4 mg + semaglutide 2.4 mg, n=2,108), semaglutide alone (n=302), cagrilintide alone (n=302), and placebo (n=705), for 68 weeks¹. The trial reports its results under two different statistical estimands, and this article gives both rather than the single more flattering number, because both point the same direction:

• •Treatment-policy estimand (intention-to-treat — counts everyone as randomized, regardless of whether they stayed on the drug): semaglutide alone -14.9%, cagrilintide alone -11.5%.
• •Trial-product estimand (as the drugs were actually taken as intended): semaglutide alone -16.1%, cagrilintide alone -11.8%.

Under either estimand, cagrilintide's own monotherapy arm trailed semaglutide's by roughly 3.4 to 4.3 percentage points — a real, trial-confirmed gap, not a rounding artifact of which estimand got quoted. It's a genuinely counterintuitive result for a drug this far along in a real regulatory pipeline: the newer amylin mechanism, tested head-to-head against an already-approved GLP-1 drug in the same trial, came in weaker on its own.

One adjacent finding is worth reporting alongside it rather than omitting, because the trial reported both: cagrilintide's gastrointestinal-adverse-event rate was meaningfully lower than semaglutide's in the same population — 54.0% of the cagrilintide-alone group reported a GI adverse event, versus 73.8% of the semaglutide-alone group¹. Cagrilintide's weaker weight-loss result did not come with a worse tolerability profile than semaglutide's in this trial — if anything the reverse. That doesn't offset the efficacy gap for anyone whose goal is weight loss specifically, but it's a real, reported difference between the two mechanisms, not just a case of cagrilintide losing on every axis at once.

What the CagriSema combination data shows

The combination is where cagrilintide's trial data gets more impressive, and where Novo Nordisk's regulatory filing actually rests. In REDEFINE-1's same four-arm comparison, CagriSema reached -20.4% (treatment-policy estimand) or -22.7% (trial-product estimand) — clearly ahead of either monotherapy arm and of placebo (-3.0% / -2.3%)¹. That combination-beats-either-alone pattern isn't a one-trial result:

• •REDEFINE-2 tested CagriSema in adults with overweight/obesity and type 2 diabetes — a harder population to move the scale on, since diabetes itself blunts weight-loss response to most therapies. Two arms only (no separate semaglutide-alone or cagrilintide-alone comparison in this trial): CagriSema reached -13.7% versus -3.4% for placebo².
• •REDEFINE-5 tested CagriSema head-to-head against semaglutide alone (no placebo or cagrilintide-alone arm) in an east-Asian population across Japan and Taiwan: CagriSema reached -18.4% versus -11.9% for semaglutide alone — a smaller absolute gap than REDEFINE-1's, in a different population, but the same direction³.

Read across all three trials, the pattern holds: CagriSema consistently outperforms semaglutide alone, in every population Novo Nordisk has published data for so far. That is the actual evidentiary basis for the FDA filing described below — and it is specifically a claim about the combination, built on combination-arm data, not a claim that transfers to cagrilintide taken by itself.

The current FDA status — both cagrilintide alone and CagriSema

Cagrilintide by itself has never been filed with FDA. A direct openFDA Drugs@FDA query for "cagrilintide" returns no matching application, and DailyMed's own archive of FDA-approved drug labeling returns zero results for "cagrilintide" — there is no NDA, no BLA, and no approved label for the molecule on its own, filed or otherwise. Novo Nordisk's regulatory strategy for cagrilintide has been combination-only from the start.

What has been filed is CagriSema. Novo Nordisk submitted a New Drug Application to FDA for the fixed-dose cagrilintide 2.4 mg / semaglutide 2.4 mg combination on December 18, 2025, built on the REDEFINE-1 and REDEFINE-2 data above (roughly 4,600 participants combined across the two trials). The company's own announcement states FDA is expected to review the application in 2026, without a confirmed decision date. As of this review, no FDA action, extension, or decision on that application has been reported, and DailyMed and openFDA both return zero results for "cagrisema" as well — a filed, pending application is not an approved product, and neither database will show one until FDA actually acts.

What this means if you're considering a compounded cagrilintide product

The two most important facts in this article, put together, point at the same conclusion. First: a compounding pharmacy can only ever prepare cagrilintide alone. CagriSema is a Novo Nordisk fixed-dose combination product built around a patented formulation and, if approved, would be a branded, non-compoundable drug — no compounded product will ever legitimately be "CagriSema," regardless of what a seller's marketing implies. Second: cagrilintide alone is the weaker performer of the two monotherapies REDEFINE-1 tested, underperforming semaglutide by a real, trial-confirmed margin under both statistical estimands the trial reported.

That means the number worth holding onto, for anyone specifically evaluating compounded cagrilintide rather than an approved GLP-1 drug, is 11.8% (or 11.5%, depending on estimand) — not 22.7%. The combination's more impressive result describes a different product, tested with a different drug it was administered alongside, that no compounding pharmacy can lawfully replicate. Citing CagriSema's trial results to sell compounded cagrilintide alone is citing the wrong arm of the trial. Beyond that substitution, the same caveats our tirzepatide-vs-semaglutide evidence review makes about any head-to-head GLP-1 trial apply here too: a published trial result describes what was measured in a controlled, dosed, monitored study population — not the identity, purity, or concentration of a specific vial from a specific seller. Our cagrilintide reconstitution calculator covers that distinction and the fuller regulatory-status detail directly; it does the vial-to-syringe arithmetic without validating the product itself, because — as this review confirms independently — there is currently no FDA-approved cagrilintide product or agency-set dosing standard to validate it against.