- People with obesity or overweight and type 2 diabetes lost up to 13.1% of their body weight with survodutide over 76 weeks.
- HbA1c fell by up to 1.21 percentage points, compared with almost no change with placebo.
- The medicine remains experimental, and gastrointestinal side effects caused a meaningful number of participants to stop treatment.
An experimental weekly injection targeting two metabolic hormone pathways has produced significant weight loss and improved blood glucose in adults with type 2 diabetes.
Survodutide activates both the GLP-1 and glucagon receptors.
That makes it different from semaglutide, which primarily acts on GLP-1, and Mounjaro (tirzepatide), which targets GLP-1 and GIP.
The phase 3 SYNCHRONIZE-2 trial investigated survodutide in adults with overweight or obesity and type 2 diabetes.
After 76 weeks, participants receiving the drug lost up to an average of 13.1% of their starting body weight, compared with 3.1% among people receiving placebo.
Up to 79.3% of people taking survodutide lost at least 5% of their starting weight, compared with 32.7% receiving placebo.
The findings add to a rapidly expanding body of evidence around GLP-1 and multi-hormone weight-loss medicines.
Blood glucose also improved
Participants began the study with an average HbA1c of around 7.4%.
Survodutide lowered HbA1c by up to 1.21 percentage points, compared with a reduction of only 0.03 percentage points with placebo.
HbA1c is one of the principal measures used to assess longer-term blood glucose control in type 2 diabetes.
Up to 29.5% of participants receiving survodutide reached an HbA1c below 5.7%, compared with 4% receiving placebo.
That is below the usual diagnostic range for diabetes.
However, it should not be described as permanent reversal or remission.
The participants were still receiving an active glucose-lowering medicine when their HbA1c was measured.
Why could weight loss help diabetes?
Body weight and type 2 diabetes are closely linked for many people because excess visceral fat can contribute to insulin resistance.
Reducing excess weight can improve the body’s response to insulin and make glucose easier to manage.
The survodutide study also reported reductions in waist circumference.
At the strongest response, waist circumference fell by around 11.1cm compared with 3.5cm with placebo.
This matters because abdominal or visceral fat is particularly strongly associated with insulin resistance and type 2 diabetes.
Fasting glucose and measures of insulin resistance also improved.
How is survodutide different?
The drug’s glucagon activity is one of the main reasons researchers are interested in it.
Glucagon is commonly known as a hormone that raises blood glucose.
However, glucagon receptor activation can also affect energy expenditure and fat metabolism.
When combined carefully with GLP-1 receptor activation, researchers hope this could increase weight loss while retaining glucose-lowering effects.
This follows the broader trend towards drugs that activate more than one metabolic pathway.
Tirzepatide targets GLP-1 and GIP, while several experimental medicines are now targeting two or even three receptors simultaneously.
How does it compare with Mounjaro or Wegovy?
It would be misleading to compare the percentages directly and conclude that one medicine is better.
SYNCHRONIZE-2 compared survodutide with placebo.
It did not directly compare survodutide with semaglutide or tirzepatide.
Different trials also involve different participants, treatment durations, doses and statistical methods.
Head-to-head studies provide much stronger evidence for comparisons between medicines.
The recent Diabetes.co.uk review of the wider field showed just how quickly GLP-1 and co-agonist treatments are evolving.
Side effects were important
The most commonly reported adverse effects were gastrointestinal.
These included:
- nausea
- vomiting
- diarrhoea
- constipation
This is broadly consistent with the wider GLP-1 class.
However, around 18% of participants receiving survodutide stopped treatment because of gastrointestinal side effects, compared with 1.2% of those receiving placebo.
That is not a trivial figure.
The developers have suggested that more flexible dose escalation may improve tolerability in future trials, but that still needs to be demonstrated.
People using existing GLP-1 medicines should also be aware that digestive symptoms are common and that a smaller number of complications require urgent assessment. Diabetes.co.uk has a fuller guide to when GLP-1 side effects may become more serious.
What happens when treatment stops?
This study does not answer that question.
It is particularly relevant because research across existing GLP-1 treatments suggests that a substantial amount of lost weight can return after medication is stopped.
If survodutide eventually reaches clinical practice, researchers will therefore need to establish whether it is best viewed as a long-term treatment and what happens after withdrawal.
What does it mean for the UK?
Survodutide is not currently available as a routine UK diabetes or obesity treatment.
It remains under clinical development.
For now, established therapies remain the relevant options for people with type 2 diabetes, including lifestyle changes, conventional glucose-lowering medicines and, where appropriate, treatments such as Mounjaro.
The more important question is whether survodutide eventually improves outcomes beyond weight and HbA1c.
Future evidence will need to show whether treatment reduces complications such as cardiovascular disease, kidney disease and premature death, while remaining tolerable enough for long-term use.
If those results are positive, survodutide could become another significant option in the rapidly expanding field of metabolic medicines.
Primary study: Survodutide Once Weekly in Adults with Obesity and Type 2 Diabetes. New England Journal of Medicine, 2026. DOI: 10.1056/NEJMoa2607219