What the main weight study found
A headline can make a trial sound like a personal forecast. It helps to slow down and ask what was actually measured.
Facts checked September 28, 2026.
Who took part
The study drug was CagriSema: cagrilintide combined with semaglutide.
Semaglutide is a different medicine that copies a body message affecting hunger and blood sugar.
REDEFINE 1 studied 3,417 adults with excess weight and without diabetes.
They received regular visits and lifestyle support alongside the study treatment.
The trial was funded by the drug maker, Novo Nordisk.
A trial is a planned study comparing treatments. These people had regular visits and help with daily habits. Keep that support in mind when talking about what the results might mean for you.
The average, with its comparison
In REDEFINE 1, average weight loss at 68 weeks was 20.4% with CagriSema, versus 3.0% with a dummy shot.
The dummy-shot group’s average was 3.0%.
A dummy shot, called a placebo, has no study drug in it.
These are group averages; a person’s result can differ.
Cagrilintide alone had a different result
The maker reported 11.5% average weight loss for cagrilintide alone in the same trial, versus 3.0% with the dummy shot.
That calculation also counted people who stopped treatment.
The groups taking only cagrilintide or only semaglutide had fewer people than the combination group.
The study’s main question was how CagriSema compared with a dummy shot.
Keep that limit in mind when reading the result for cagrilintide alone.
Why a larger headline appears
The often-quoted 22.7% for CagriSema is a calculation of what weight loss would have been if everyone had stayed on treatment.
It is not simply the average for only the people who stayed on the medicine.
The dummy-shot result calculated the same way was 2.3%.
It is a different calculation from the 20.4% result above.
As of September 28, 2026, a study asking whether CagriSema reduces heart attacks and strokes was still running.
Weight loss alone does not tell us whether this medicine prevents those problems.
Read the published trial record