SYNCHRONIZE-1 published: survodutide is the first dual GLP-1/glucagon agonist with full Phase 3 obesity data

A Phase 3 trial called SYNCHRONIZE-1 has been published in the New England Journal of Medicine, giving the first full late-stage look at survodutide, a once-weekly injectable drug that acts on two hormone receptors at once: the glucagon receptor and the GLP-1 receptor ^[1]. Unlike Ozempic, Wegovy, and Mounjaro, which target GLP-1 (and, for tirzepatide, also GIP), survodutide adds glucagon receptor activity to the mix ^[1]. It is made by Boehringer Ingelheim, which funded the study ^[1].

The trial enrolled 725 adults with obesity, or with a BMI of 27 or higher plus at least one obesity-related health problem, but excluded people with diabetes ^[1]. Participants were randomly assigned to receive survodutide at a target dose of 3.6 mg or 6.0 mg, or a placebo, once a week for 76 weeks, along with lifestyle counseling ^[1]. The average participant was 47 years old, had a BMI of 37.9, and weighed about 108.8 kg (roughly 240 pounds) at the start ^[1].

At 76 weeks, average body weight had dropped 12.2% in the 3.6 mg group and 13.0% in the 6.0 mg group, compared with 5.4% in the placebo group, using the study's primary statistical method, which accounts for people who stopped the drug early or added other weight-loss treatments ^[1]. About 73% of people on the lower dose and 72% on the higher dose lost at least 5% of their body weight, compared with 46% on placebo ^[1]. Every comparison between survodutide and placebo was statistically significant ^[1].

Side effects followed a pattern familiar to people who have taken other GLP-1 drugs. Gastrointestinal symptoms, described as typically mild to moderate, were reported by about 81% of people on the lower dose and about 90% on the higher dose, compared with about 48% on placebo ^[1]. No deaths were reported in the trial ^[1].

Why it matters for patients

Survodutide is not yet approved in the United States, so this trial does not change what is available at a pharmacy today. What it does show is that a drug working through a different combination of hormone pathways than existing GLP-1 medicines can produce weight loss in a similar range to what current injectable options have shown in their own trials ^[1]. For patients who do not tolerate or respond well to semaglutide or tirzepatide, a differently designed drug like survodutide could eventually offer another choice, though that possibility depends on future regulatory review and additional data ^[1].

The side effect pattern reported here, mostly gastrointestinal and more common at the higher dose, is consistent with what patients already taking GLP-1 drugs may recognize from their own experience, though the exact rates differ by drug and trial ^[1]. The study also excluded people with diabetes, so it is not yet known how survodutide performs in that population, or how its long-term safety compares with approved drugs over more than 76 weeks ^[1].

What happens next

The study was published in NEJM's August 20, 2026 print issue after appearing online on June 7, 2026 ^[1]. The article notes it was updated on July 23, 2026, though the sources reviewed here do not specify what that update changed ^[1]. No regulatory filing date, US approval timeline, or pricing information appears in the available material, so those details are not yet known.