What CagriSema is
CagriSema is a fixed-dose combination of two peptides: cagrilintide 2.4 mg, a long-acting amylin receptor agonist, and semaglutide 2.4 mg, a long-acting glucagon-like peptide-1 (GLP-1) receptor agonist. Both constituents are peptides; the combination is given as a once-weekly subcutaneous injection and is being developed by Novo Nordisk for weight management (the REDEFINE programme) and for type 2 diabetes (the REIMAGINE programme).
It is the most clinically advanced attempt to pair an amylin analogue with an incretin. The rationale is mechanistic rather than incremental: amylin and GLP-1 act on overlapping but distinct appetite-regulatory circuits, and the sponsors have argued the two molecules produce complementary effects on satiety and energy intake. That reasoning is a hypothesis the trials test; it is not itself an outcome.
This page records what the published Phase 3 record shows, what it does not show, and the UK regulatory position. It is a reference note on a peptide medicine, not a research-use-only compound, and nothing here is consumption or prescribing guidance.
The Phase 3 record
REDEFINE 1 — obesity, published in the NEJM (2025)
REDEFINE 1 randomised adults with overweight or obesity and at least one weight-related complication, without diabetes, to CagriSema 2.4 mg/2.4 mg or placebo for 68 weeks, alongside lifestyle intervention. The trial met its co-primary endpoints and was published in The New England Journal of Medicine in June 2025.
- On the treatment-regimen estimand (effect regardless of whether participants stayed on treatment), mean weight reduction was 20.4% with CagriSema versus 3.0% with placebo.
- On the adherence estimand (effect if all participants had adhered), mean weight reduction was 22.7% versus 2.3% with placebo.
Both differences were statistically significant (p<0.001). The adherence estimand figure of 22.7% is the number most often quoted in secondary coverage; readers should note it is an estimate of effect under full adherence, not the observed average in the trial population.
REDEFINE 4 — head-to-head miss versus tirzepatide (February 2026)
REDEFINE 4 was an open-label Phase 3 trial comparing CagriSema 2.4 mg/2.4 mg with tirzepatide 15 mg over 84 weeks in adults with obesity. Novo Nordisk announced headline results on 23 February 2026: CagriSema produced 23% mean weight loss at 84 weeks, but the trial did not meet its primary endpoint of non-inferiority against tirzepatide 15 mg.
The company reported that the safety profile was consistent with incretin- and amylin-based therapies, with gastrointestinal events predominating, mostly mild to moderate and diminishing over time. A higher-dose CagriSema trial (the REDEFINE 11 readout, and a planned higher-dose study) is designed to test whether the full weight-loss potential of the combination exceeds what these fixed doses achieved.
A non-inferiority miss is a specific, narrow result: it means the trial could not demonstrate that CagriSema was no worse than tirzepatide on the prespecified margin. It does not mean CagriSema was ineffective against placebo, and it is not the same as a superiority claim running the other way.
REIMAGINE 1–3 — type 2 diabetes, published in The Lancet journals (2026)
Results from the REIMAGINE programme in type 2 diabetes were presented at the American Diabetes Association 2026 Scientific Sessions and published simultaneously:
- REIMAGINE 1 — a 40-week, randomised, double-blind, placebo-controlled Phase 3a trial in 189 adults with type 2 diabetes inadequately controlled on diet and exercise. Both CagriSema doses (1 mg/1 mg and 2.4 mg/2.4 mg) met the primary HbA1c endpoint versus placebo. Published in The Lancet Diabetes & Endocrinology.
- REIMAGINE 2 — a 68-week, double-blind, randomised, controlled Phase 3 trial in 2,728 adults with type 2 diabetes inadequately controlled on metformin with or without an SGLT2 inhibitor, comparing CagriSema with its individual components. The sponsor reported superior HbA1c reduction (up to 1.91 percentage points from a mean baseline HbA1c of 8.2%) and superior weight loss (up to 14.2%), with superiority established against both semaglutide and cagrilintide alone. Published in The Lancet Diabetes & Endocrinology.
- REIMAGINE 3 — a 40-week, randomised, double-blind, placebo-controlled trial of both CagriSema doses as an add-on to once-daily basal insulin in 274 adults with type 2 diabetes. Both doses met the primary HbA1c endpoint versus placebo. Published in The Lancet.
All three trials evaluated the combination product. They cannot be read as evidence about either constituent dosed on its own.
What the record does not show
The published evidence does not support several claims that circulate in secondary coverage:
- There is no demonstrated mortality or cardiovascular-outcome benefit. The reported endpoints are weight, HbA1c and tolerability. Cardiovascular outcome data for CagriSema are not established by these trials.
- Cross-trial comparisons are not evidence of relative efficacy. Comparing a REDEFINE result with a semaglutide or tirzepatide trial run in a different population, at a different duration and using a different estimand isolates no causal effect. REDEFINE 4 is the one head-to-head data point, and it missed its non-inferiority target.
- The estimand matters. The 22.7% and 20.4% figures in REDEFINE 1 answer different questions, and the difference between them is the size of the treatment-discontinuation effect — which is itself clinically relevant information, not a nuisance.
- Long-term durability is unresolved. Maintenance of weight loss beyond the trial windows, and the effect of withdrawal, are open questions that the extension phases are designed to address.
UK regulatory position
As of September 2026 CagriSema holds no marketing authorisation from the MHRA and is not available for prescription in the UK, privately or on the NHS. Its regulatory progress has been in another jurisdiction: Novo Nordisk submitted a New Drug Application to the US Food and Drug Administration for weight management in December 2025, with a decision anticipated in late 2026. That is a separate assessment and does not confer any UK status.
For any peptide medicine to be lawfully marketed in the UK it requires an MHRA marketing authorisation, granted after assessment of quality, safety and efficacy and subject to the Human Medicines Regulations 2012. Authorisation is only the first step to NHS access: a positive NICE technology appraisal and NHS commissioning are separate, later gates — the pattern set by other GLP-1 receptor agonists, where the interval from MHRA authorisation to NHS rollout has run to roughly 19 months.
Because it is unlicensed, there is no lawful UK route to obtain CagriSema other than participation in an authorised clinical trial. Compounds that are unlicensed are sometimes marketed under "research use only" framing; that framing does not create a legal route to personal supply of a medicine, and the MHRA has taken enforcement action against vendors marketing peptide products for human use.
Why this sits in a peptide reference
CagriSema belongs to the licensed-medicine end of the peptide spectrum, alongside semaglutide, tirzepatide and the authorised oral GLP-1 tablet — not the unlicensed research-peptide grey area. It is included here because the Phase 3 record is a useful calibration point: it shows how much weight-loss effect is currently achievable with a well-powered two-peptide programme, and it shows how a genuine head-to-head result (a non-inferiority miss) differs from the cross-trial arithmetic that dominates peptide marketing.
Readers looking for the evidence behind the individual components and the comparator should see the linked compound profiles for cagrilintide, semaglutide and tirzepatide.
This article is AI-researched and editorially reviewed. It is provided for research and educational purposes only and is not medical advice. Research peptides are not licensed for human consumption in the UK.