CagriSema vs Tirzepatide: What Do the New Trial Results Really Show?

A new set of phase 3 trial results has put CagriSema back into the weight-management spotlight.

On 21 September 2026, Novo Nordisk announced new results from two late-stage studies of CagriSema, an investigational once-weekly injection combining cagrilintide, an amylin analogue, with semaglutide, the GLP-1 medicine used in Wegovy.

The headline attracting attention is that, in one trial, CagriSema produced more weight loss than tirzepatide 5 mg.

But there are some important details behind that headline.

What did the REIMAGINE 5 trial find?

REIMAGINE 5 studied adults with type 2 diabetes whose blood glucose was not adequately controlled with metformin, an SGLT2 inhibitor, or both.

After 60 weeks, participants receiving CagriSema 1.0 mg/1.0 mg had an estimated average weight reduction of 12.4%, compared with 9.1% for people receiving tirzepatide 5 mg.

CagriSema also met the study's goal of being non-inferior to tirzepatide for lowering HbA1c.

These results are encouraging, but they do not mean that CagriSema has been shown to produce more weight loss than tirzepatide at every dose.

The comparator in this trial was specifically tirzepatide 5 mg. Tirzepatide is also used at higher doses, so this should not be interpreted as a head-to-head comparison with maximum-dose tirzepatide.

The participants also had type 2 diabetes, so the findings should not automatically be applied to every person receiving treatment for obesity.

What about people without diabetes?

Novo Nordisk also announced results from REDEFINE 9, involving adults living with overweight or obesity.

At week 68, participants receiving CagriSema 1.0 mg/1.0 mg achieved an estimated 21.0% reduction in body weight, compared with 2.0% with placebo. The company also reported improvements in measures including blood pressure, waist-to-height ratio and fasting lipids.

Again, this was a comparison with placebo rather than Mounjaro, Wegovy or another active weight-management medicine.

Is CagriSema available in the UK?

No. CagriSema remains an investigational medicine and is not currently a routine UK weight-management treatment.

The results announced on 21 September are also topline company-reported findings. Full peer-reviewed publication of these particular results will be important before firm conclusions can be drawn about comparative effectiveness and safety.

Patients should therefore be cautious about websites or social-media sellers claiming to supply CagriSema, cagrilintide or other investigational weight-loss medicines before they are appropriately authorised.

Does this mean patients should change from Mounjaro or Wegovy?

No.

People currently taking an effective, licensed weight-management treatment should not stop or switch medication because of an early trial announcement.

Choosing treatment involves much more than headline percentage weight loss. Tolerability, medical history, previous response, side effects, route of administration, maintenance needs and individual preference all matter.

The results are exciting because they give us another glimpse of how obesity treatment may evolve — particularly through combinations targeting more than one appetite-regulating pathway.

How Pharmulous can help

At Pharmulous, our focus is on individualised, doctor-led weight management rather than simply chasing the newest medicine or the highest dose.

For patients using currently licensed treatments, our clinical team can review progress, tolerability, treatment options and longer-term maintenance needs. Where appropriate, the aim is to use an effective and sustainable approach while maintaining clinical safety, nutrition and overall health.

As new weight-management medicines progress through research and UK regulatory assessment, we will continue to review the evidence and explain what genuinely changes for patients and what does not.