This page compares Cagrilintide + Semaglutide — the fixed combination developed as CagriSema — with Tirzepatide. It does not provide dosing guidance or treatment recommendations.
Two bets on beating the single agonist
Semaglutide set the benchmark that everything since has been designed to beat, and the field split into two strategies for beating it. CagriSema keeps the GLP-1 agonist and adds a second hormone system beside it: cagrilintide, a long-acting analog of amylin, the hormone co-secreted with insulin by pancreatic beta cells. Amylin promotes satiety through amylin and calcitonin receptors concentrated in the hindbrain — a pathway that runs parallel to GLP-1 rather than overlapping it, which is the rationale for combining the two instead of pushing one receptor harder.
Tirzepatide takes the opposite route: one molecule, two incretin receptors. It is built on the native GIP sequence and modified so that it also activates the GLP-1 receptor, with a fatty-diacid chain that binds albumin and gives it a half-life of about five days. In receptor-knockout work during discovery, its glucose effects required both receptors — it behaves as a genuine dual agonist rather than a GLP-1 drug carrying a passenger sequence.
The practical difference this creates is one of pharmaceutical form. CagriSema is a fixed-ratio co-formulation of two active ingredients at 2.4 mg each; the ratio was fixed during phase 1b and 2 development and cannot be tuned independently in the products under review. Tirzepatide is a single ingredient, so its GIP and GLP-1 activity are welded together by chemistry. Neither approach lets a prescriber dial one arm up and the other down.
Head to head at a glance
| Dimension | CagriSema | Tirzepatide |
|---|---|---|
| Mechanism / receptors | Two hormone systems, two molecules. Cagrilintide is a long-acting amylin analog acting at amylin and calcitonin receptors, largely in the hindbrain; semaglutide is a GLP-1 receptor agonist. Satiety signalling arrives down two parallel routes. | Two incretin receptors, one molecule. Built on the native GIP sequence and engineered to also activate the GLP-1 receptor, with a C20 fatty-diacid chain that binds albumin and stretches the half-life to roughly five days. |
| Components | A fixed-ratio co-formulation of two distinct active ingredients — cagrilintide 2.4 mg and semaglutide 2.4 mg — delivered in one weekly subcutaneous injection, not two co-injected vials. | A single active ingredient marketed under two brand names: Mounjaro for type 2 diabetes and Zepbound for weight management and sleep apnea. Same molecule, same strengths, separate labels. |
| Regulatory status | Investigational. No approved indication in any jurisdiction. Novo Nordisk filed a US New Drug Application on 18 December 2025 based on REDEFINE 1 and REDEFINE 2, with FDA review expected during 2026. | Approved. Mounjaro (May 2022) for type 2 diabetes; Zepbound (November 2023) for chronic weight management, extended in December 2024 to moderate-to-severe obstructive sleep apnea in adults with obesity. |
| Phase 3 weight result (obesity) | REDEFINE 1 (n=3,417, 68 weeks, adults without diabetes): mean body-weight change −20.4% vs −3.0% for placebo, a difference of 17.3 percentage points on the treatment-policy estimand. | SURMOUNT-1 (n=2,539, 72 weeks): −15.0% at 5 mg, −19.5% at 10 mg and −20.9% at 15 mg vs −3.1% for placebo. 57% of the 15 mg group lost at least 20% of body weight. |
| Phase 3 weight result (type 2 diabetes) | REDEFINE 2 (n=1,206, 68 weeks): −13.7% vs −3.4% for placebo, with 73.5% of the treated group reaching an HbA1c of 6.5% or less versus 15.9% on placebo. | SURPASS-2 (n=1,879, 40 weeks) tested the glycemic question directly against semaglutide 1 mg: HbA1c fell 2.01–2.30 points vs 1.86, with 1.9–5.5 kg more weight lost at 5, 10 and 15 mg. |
| Gastrointestinal adverse events | REDEFINE 1: 79.6% vs 39.9% on placebo — nausea, vomiting, diarrhea, constipation or abdominal pain, described as mainly transient and mild-to-moderate. REDEFINE 2: 72.5% vs 34.4%. | SURMOUNT-1: gastrointestinal events were the most common adverse events, mostly mild to moderate and concentrated in dose escalation. Discontinuation for adverse events 4.3% / 7.1% / 6.2% at 5 / 10 / 15 mg vs 2.6% for placebo. |
| Dosing pattern | Once-weekly subcutaneous injection titrated over months toward a 2.4 mg / 2.4 mg maintenance dose. No approved regimen exists anywhere; every number describes a trial protocol, not a label. | Once-weekly subcutaneous injection. Both labels start at 2.5 mg and escalate in 2.5 mg steps no faster than every four weeks to a maximum of 15 mg; the sleep-apnea indication is dosed at 10 or 15 mg weekly. |
| Availability | No pharmacy product exists. Legitimate supply is confined to the sponsor's clinical trials, so anything sold online as “CagriSema” or “cagrilintide” is unapproved gray-market material of unverified identity and purity. | Prescription pharmacy product supplied as single-dose pens and vials in six strengths from 2.5 mg to 15 mg, plus a KwikPen. Vials sold as “research use only” tirzepatide are not the approved medicine. |
Why −20.4% and −20.9% is not a tie
REDEFINE 1 randomised 3,417 adults with obesity, or overweight plus at least one obesity-related complication and no diabetes, in a 21:3:3:7 ratio to CagriSema, semaglutide alone, cagrilintide alone or placebo. Mean body-weight change at week 68 was −20.4% against −3.0% for placebo (Garvey et al., NEJM 2025). SURMOUNT-1 randomised 2,539 adults to a tirzepatide dose ladder for 72 weeks; the 15 mg arm reached −20.9% against −3.1% for placebo (Jastreboff et al., NEJM 2022). Half a percentage point apart.
That half-point is arithmetic between two separate trials, not evidence that the two treatments are equivalent. The studies ran for different durations (68 versus 72 weeks), enrolled in different years across different site networks, used different eligibility filters, and reported under different analysis conventions. Their placebo arms happened to land close together (−3.0% and −3.1%), which is mildly reassuring about comparability, but a matched placebo response is not the same as a matched population. Between two independent phase 3 trials, a 0.5-point gap sits well inside the range you would expect from chance and design differences alone.
The estimand question makes the point concrete. The −20.4% figure is the treatment-policy estimand, consistent with intention-to-treat — everyone counted as randomised, regardless of whether they stayed on drug. Novo Nordisk’s own filing announcement quotes approximately 23% for the same trial under a different analysis (Novo Nordisk, 18 December 2025). The same pattern shows in the diabetes trial: NEJM reports −13.7% for REDEFINE 2 (Davies et al., NEJM 2025) while the sponsor quotes 15.7%. Both numbers are real; they answer slightly different questions. A headline weight percentage means very little without the trial, the population and the estimand attached to it.
One further piece of context matters for reading REDEFINE 1 honestly. The result landed below what the development programme had led many observers to expect from a combination whose earlier, smaller studies looked steeper: the 32-week phase 2 trial in type 2 diabetes (n=92) produced −15.6% for CagriSema against −5.1% for semaglutide alone (Frías et al., The Lancet 2023), and the 20-week phase 1b study reached 15.4–17.1% weight reduction in a 95-participant cohort (Enebo et al., The Lancet 2021). Effect sizes shrinking as a programme scales from small, tightly-supervised cohorts into large phase 3 populations is the normal direction of travel, and it is the reason early numbers should not be treated as forecasts.
For completeness on the components: cagrilintide alone reached 6.0% to 10.8% weight reduction across doses in its 26-week phase 2 trial (n=706) against 3.0% for placebo, with the 4.5 mg dose modestly beating liraglutide 3.0 mg (Lau et al., The Lancet 2021). REDEFINE 1 also ran semaglutide-alone and cagrilintide-alone arms of 302 participants each, which is the internally-controlled comparison that actually isolates what the combination adds.
The gastrointestinal burden is high on both sides
In REDEFINE 1, gastrointestinal adverse events — nausea, vomiting, diarrhea, constipation or abdominal pain — were reported by 79.6% of the CagriSema group against 39.9% on placebo, described as mainly transient and mild-to-moderate. REDEFINE 2 reported 72.5% versus 34.4%. Nearly four in five participants experiencing a GI event is a large number even when most of those events are mild and most resolve, and it is the predictable cost of stacking two appetite-suppressing pathways that both slow gastric emptying.
Tirzepatide’s trials report the same dominant theme in different units. SURMOUNT-1 does not publish a single pooled GI percentage; it reports gastrointestinal events as the most common adverse events, mostly mild to moderate, occurring primarily during dose escalation, with discontinuation for adverse events at 4.3%, 7.1% and 6.2% across the 5, 10 and 15 mg arms versus 2.6% on placebo. Because the two programmes tabulate tolerability differently, the honest statement is that both carry a substantial GI burden concentrated in titration — not that one is measurably gentler than the other. Tirzepatide additionally carries a boxed warning for rodent thyroid C-cell tumors and labeled warnings covering pancreatitis, gallbladder disease and dehydration-related kidney injury (Mounjaro label, DailyMed). CagriSema has no label, so it has no boxed warning, no contraindication list and no post-marketing surveillance — an absence of characterisation, not an absence of risk.
One is approved; one is under review
Tirzepatide holds three FDA-approved indications: type 2 diabetes as Mounjaro, chronic weight management as Zepbound, and — since December 2024 — moderate to severe obstructive sleep apnea in adults with obesity, the first medication ever approved for OSA. That third indication rests on SURMOUNT-OSA, where the apnea–hypopnea index fell by 25.3 and 29.3 events per hour across two phase 3 trials against roughly 5 for placebo (Malhotra et al., NEJM 2024), and it is dosed at 10 or 15 mg weekly on the Zepbound label (DailyMed). Tirzepatide also has withdrawal data: in SURMOUNT-4 (n=670 randomised), participants switched to placebo after a 36-week lead-in regained 14.0% of body weight over the following year while those continuing lost a further 5.5% (Aronne et al., JAMA 2024) — evidence that the class manages a chronic condition rather than curing it.
CagriSema has none of that. It is investigational everywhere, with no approved indication in any jurisdiction. A US New Drug Application was filed on 18 December 2025 for weight management in adults with obesity or overweight with a weight-related comorbidity, based on REDEFINE 1 and REDEFINE 2, with FDA review expected during 2026. The cardiovascular-outcome question is still open: REDEFINE 3 (NCT05669755) enrolled 7,101 participants with cardiovascular disease and is listed as active, not recruiting, with a completion date in October 2027.
The head-to-head trial that has already finished
The comparison this page is forced to make indirectly has been made directly — the results simply are not public. NCT06131437 is a phase 3 trial that randomised 809 adults with obesity to CagriSema 2.4 mg / 2.4 mg or tirzepatide 15 mg once weekly. It is listed as completed, with a completion date of 9 January 2026, and as of this page’s last update the registry shows no posted results and PubMed shows no publication. Two further phase 3 trials in type 2 diabetes have also completed against tirzepatide comparators: NCT06221969 (n=1,024, CagriSema 2.4/2.4 mg versus tirzepatide 15 mg) and NCT06534411 (n=1,023, at the lower 1.0/1.0 mg and 5 mg dose levels).
Until those read out, the only real head-to-head anchor in this class is SURPASS-2, which pitted tirzepatide against semaglutide 1 mg in 1,879 adults with type 2 diabetes over 40 weeks: HbA1c fell 2.01, 2.24 and 2.30 percentage points at 5, 10 and 15 mg against 1.86 for semaglutide, with 1.9 to 5.5 kg more weight lost (Frías et al., NEJM 2021). Note the ceiling on what even that trial establishes: it used semaglutide’s 1 mg diabetes dose, not the 2.4 mg obesity dose that sits inside CagriSema. Every comparison on this page is provisional until the direct trials publish.
How to dive deeper
- Cagrilintide + Semaglutide overview · benefits · side effects · dosing education · research
- Cagrilintide overview · research — the amylin component on its own.
- Tirzepatide overview · benefits · side effects · dosing education · research
- Semaglutide overview — the GLP-1 agonist that forms half of CagriSema and the benchmark both strategies were built to beat.
- Related comparisons: semaglutide vs tirzepatide · tirzepatide vs retatrutide · compare hub
- Background questions: top peptides for weight loss · how weight-loss peptides work · are GLP-1 peptides safe long term · regaining weight after stopping · weight-loss peptides and muscle mass
References & searches
Every claim above links its primary source. To check the wider literature and the trial registry yourself: