Survodutide, an experimental once-weekly injection from Boehringer Ingelheim that acts on both the GLP-1 and glucagon receptors, reduced body weight by 8.2% to 9.8% over 76 weeks in adults with obesity and type 2 diabetes, against 3.9% on placebo, in a phase 3 trial published in the New England Journal of Medicine on 1 October. The paper describes the drug as investigational, so nothing changes at the pharmacy. What changes is the evidence: a second way of targeting weight now has peer-reviewed phase 3 results in people with diabetes.
What SYNCHRONIZE-2 measured
The trial, registered as NCT06066528 and funded by Boehringer Ingelheim, randomly assigned 752 adults with type 2 diabetes and a body-mass index of 27 or more, in equal thirds, to weekly survodutide at 3.6 mg, survodutide at 6.0 mg, or placebo, double-blind. Participants averaged 55.7 years of age, a BMI of 36.5 and an HbA1c of 7.4%; 49.3% were men. It had two primary endpoints: the percentage change in body weight at week 76, and the share of people who lost at least 5%.
Counting everyone who was randomised, whether or not they kept taking the drug, weight fell by 8.2% on 3.6 mg (95% confidence interval 7.2% to 9.2%), 9.8% on 6.0 mg (8.8% to 10.8%) and 3.9% on placebo (2.9% to 4.9%). Subtracting placebo leaves 4.3 percentage points for the lower dose and 5.9 for the higher. The two dose intervals overlap, so the trial does not cleanly separate the doses from each other. At least 5% weight loss was reached by 57.6%, 64.5% and 35.1% of participants respectively. HbA1c fell by 0.9 and 0.8 percentage points on the two doses, and by 0.2 on placebo.
Gastrointestinal side effects were reported by 72.8% of people on 3.6 mg and 77.7% on 6.0 mg, against 38.6% on placebo: roughly twice the placebo rate. The authors describe them as generally mild to moderate and transient.
How it sits beside semaglutide and tirzepatide
People with type 2 diabetes tend to lose less weight on these drugs than people without it, which is why each drug is tested separately in this group. Two earlier trials in the same population give a rough frame. In STEP 2, published in The Lancet in 2021, semaglutide 2.4 mg produced 9.6% weight loss at 68 weeks against 3.4% on placebo, a difference of 6.2 points. In SURMOUNT-2, published in The Lancet in 2023, tirzepatide 10 mg and 15 mg produced 12.8% and 14.7% at 72 weeks against 3.2% on placebo, differences of 9.6 and 11.6 points.
On those numbers, survodutide’s higher dose lands close to semaglutide and well short of tirzepatide. That comparison should be held loosely: the trials ran for different lengths, enrolled different people at different times and never tested the drugs against each other. The SYNCHRONIZE-2 placebo group also lost more weight (3.9%) than either earlier placebo group, which narrows survodutide’s placebo-adjusted figure.
The result is broadly in line with the drug class as a whole. A meta-analysis of 19 randomised trials of GLP-1/glucagon dual agonists (mazdutide, survodutide, cotadutide and efinopegdutide), published in Diabetes, Obesity and Metabolism on 29 September, put the average weight loss beyond placebo at 7.15%, with more adverse events overall (risk ratio 1.16) but no increase in serious ones (risk ratio 0.90). For how the approved drugs work, see our GLP-1 research hub.
What is not yet known. This report is based on the published abstract; the full paper, including any body-composition data, was not available to us. The trial was designed and paid for by the manufacturer. It measured weight and blood sugar, not heart attacks, strokes or deaths, so it says nothing about cardiovascular outcomes. Seventy-six weeks is longer than many weight trials, but it does not show what happens after people stop. The drug has no approval and no US price. And the gastrointestinal burden, reported by more than three in four people on the higher dose, is the figure most likely to decide how many people would stay on it outside a trial.
Sources: Wharton S, le Roux CW, et al. Survodutide once weekly in adults with obesity and type 2 diabetes. N Engl J Med, published online 1 October 2026 (SYNCHRONIZE-2, NCT06066528). Amjad MM, et al. Efficacy and safety of dual GLP-1/glucagon receptor agonism in overweight and obesity: a class-specific systematic review and meta-analysis. Diabetes Obes Metab, 29 September 2026. Davies M, et al. Semaglutide 2.4 mg once a week in adults with overweight or obesity, and type 2 diabetes (STEP 2). Lancet, March 2021. Garvey WT, et al. Tirzepatide once weekly for the treatment of obesity in people with type 2 diabetes (SURMOUNT-2). Lancet, August 2023.
