Investigational — not approved or available to prescribe.
Main trial result
16.6%
Stage
Phase 3
Timeline (not confirmed)
Not yet known — Boehringer Ingelheim has not given a date
Form
Weekly injection
What it is
Survodutide is Boehringer Ingelheim’s investigational once-weekly injectable glucagon/GLP-1 receptor dual agonist for obesity, licensed from Zealand Pharma. In the Phase 3 SYNCHRONIZE-1 trial, adults with obesity or overweight without type 2 diabetes lost an average of 16.6% of their body weight at 76 weeks on the 6.0 mg dose, among people who kept taking it (the efficacy estimand), compared with 3.2% on placebo. Counting everyone who started, including the roughly one in four who stopped treatment, average weight loss was 13.0% at 6.0 mg, versus 5.4% on placebo. It is investigational — not approved — and Boehringer Ingelheim has not given a timeline for filing or approval. Results from a companion trial in people who also have type 2 diabetes (SYNCHRONIZE-2) had not been reported as of September 2026, and results in that population may differ.
Why this matters:
Survodutide activates two different hormone receptors — glucagon and GLP-1 — rather than GLP-1 alone, which is how most approved obesity drugs work. Boehringer Ingelheim and Zealand Pharma say this dual mechanism may act more directly on liver fat, and a Phase 3 sub-study has shown reductions in liver and visceral fat alongside weight loss. These treatments are still under investigation, and results in additional trials may differ from what has been reported so far.
Development stage and timeline
Current stage:
Phase 3 complete for the main obesity programme. SYNCHRONIZE-1 (without type 2 diabetes) announced topline results in April 2026, with full data presented at the American Diabetes Association’s 2026 Scientific Sessions in June 2026. SYNCHRONIZE-2 (with type 2 diabetes) and SYNCHRONIZE-3 (Japanese participants) have completed per ClinicalTrials.gov, but Boehringer Ingelheim had not reported their results as of September 2026. A cardiovascular outcomes trial (SYNCHRONIZE-CVOT) has also finished its main follow-up period.
Next milestone:
SYNCHRONIZE-2 results (people with obesity and type 2 diabetes) are expected at the EASD 2026 meeting, 28 September–2 October 2026 in Milan. No filing or approval timeline has been announced.
How it works
Survodutide is a peptide that activates both the glucagon receptor and the GLP-1 receptor — a "dual agonist," unlike GLP-1-only drugs such as semaglutide and liraglutide. GLP-1 receptor activation cuts appetite and slows stomach emptying, the same mechanism used by other GLP-1 drugs. Glucagon receptor activation is thought to raise energy expenditure and may act more directly on fat stored in the liver. It is licensed to Boehringer Ingelheim from Zealand Pharma and given as a once-weekly subcutaneous injection, gradually increased to a 3.6 mg or 6.0 mg maintenance dose.
Timeline note: In the Phase 3 SYNCHRONIZE-1 trial, weight loss was measured at 76 weeks, reaching an average of 16.6% at that timepoint on the 6.0 mg weekly dose (efficacy estimand; 13.0% counting everyone who started)
Phase 3 trial results
In the following Phase 3 trials, participants were randomly assigned to Survodutide or a dummy pill.
In the SYNCHRONIZE-1 trial, using the efficacy estimand (assuming continued treatment), participants lost an average of 16.6% of body weight on survodutide 6.0 mg weekly, versus 3.2% on placebo (p<0.0001) — an average loss of up to 39.2 lb (17.8 kg). Up to 85.1% of participants lost at least 5% of their body weight, versus 38.8% on placebo (p<0.0001). Waist circumference also improved significantly more than with placebo. Counting everyone who started (the treatment-regimen estimand), weight loss was 13.0% on 6.0 mg and 12.2% on 3.6 mg, versus 5.4% on placebo. Results were first presented at the American Diabetes Association’s 2026 Scientific Sessions.
In the SYNCHRONIZE-MASLD trial, at the 6.0 mg weekly dose, average weight loss was 12.2%, versus 1.0% on placebo. Up to 84.2% of participants had at least a 30% relative reduction in liver fat, versus 24.3% on placebo, and 61.0% reached liver fat normalization (liver fat below 5%), versus 5.7% on placebo. This is a related liver-disease trial, not the main obesity programme, and its results are reported here for context.
Early-stage data
Phase 1 and Phase 2 data only. Phase 3 trials are planned, but not yet complete. Treat these early results with caution.
In trial data, average weight loss ranged from 6.2% (0.6 mg) to 14.9% (4.8 mg, the highest dose tested), versus 2.8% on placebo, in the modified intention-to-treat population. At the 4.8 mg dose, 55% of participants lost at least 15% of their body weight, versus 6% on placebo. This was an earlier, smaller trial; the Phase 3 SYNCHRONIZE trials, which tested only the 3.6 mg and 6.0 mg doses, are described above.
Phase 3 programme
- SYNCHRONIZE-1: adults with obesity or overweight, without type 2 diabetes (725 participants) — topline results announced April 2026
- SYNCHRONIZE-2: adults with obesity or overweight and type 2 diabetes (755 participants) — completed per ClinicalTrials.gov; results expected at EASD 2026 (28 September–2 October)
- SYNCHRONIZE-3: the same design run in Japanese participants with obesity (274 participants) — completed December 2025; results not yet public
- SYNCHRONIZE-CVOT: a cardiovascular outcomes trial in about 5,531 adults with obesity and cardiovascular or chronic kidney disease — main follow-up completed per ClinicalTrials.gov; results not yet reported
- SYNCHRONIZE-MASLD: adults with obesity and metabolic dysfunction-associated steatotic liver disease (218 participants) — completed; results presented at ADA 2026
Notable findings
- ✓In a pre-specified sub-study of SYNCHRONIZE-1, survodutide produced up to a 34.0% relative reduction in visceral fat and up to 63.1% reduction in liver fat
- ✓In the related SYNCHRONIZE-MASLD trial, up to 61.0% of participants with fatty liver disease reached liver fat normalization (liver fat below 5%), versus 5.7% on placebo
What this tends to offer vs. what it involves
What this tends to offer
- ✓In the Phase 3 SYNCHRONIZE-1 trial, average weight loss at 6.0 mg was 16.6% at 76 weeks among people who kept taking it, or 13.0% counting everyone who started — versus 3.2% and 5.4% on placebo
- ✓Up to 85.1% of participants who kept taking it lost at least 5% of their body weight, versus 38.8% on placebo (72.6% vs 46.3% counting everyone who started)
- ✓In a pre-specified sub-study of SYNCHRONIZE-1, most of the weight lost was fat: lean mass made up no more than 11.3% of the total tissue-mass change
- ✓A related Phase 3 trial (SYNCHRONIZE-MASLD) found meaningful reductions in liver fat alongside weight loss in people with fatty liver disease
What this involves
- Not yet approved by any regulator — Boehringer Ingelheim has not stated a filing or approval timeline
- Gastrointestinal side effects were common in the Phase 3 trial and led roughly 1 in 5 participants to discontinue treatment because of them (19% vs. 2.9% on placebo)
- Overall treatment discontinuation because of side effects was higher on survodutide than placebo in the Phase 3 trial (about 24–25% vs. about 5%)
- SYNCHRONIZE-2, the companion trial in people with type 2 diabetes, had not reported results as of September 2026
Sources & references
- [1]SYNCHRONIZE-1 (Phase 3)725 adults with obesity or overweight and at least one weight-related condition, without type 2 diabetes · 76 weeksOn survodutide 6.0 mg weekly, average weight loss was 16.6% using the efficacy estimand, versus 3.2% with placebo (p<0.0001) — an average loss of up to 39.2 lb (17.8 kg). Up to 85.1% of participants lost at least 5% of their body weight, versus 38.8% with placebo (p<0.0001).The New England Journal of Medicine (2026) ↗
- [2]SYNCHRONIZE-MASLD (Phase 3)218 adults with obesity or overweight and metabolic dysfunction-associated steatotic liver disease (MASLD) with inflammation and/or fibrosis · 48 weeksAt the 6.0 mg weekly dose, average weight loss was 12.2%, versus 1.0% with placebo. Up to 84.2% of participants had at least a 30% relative reduction in liver fat, versus 24.3% with placebo, and 61.0% reached liver fat normalization (liver fat below 5%), versus 5.7% with placebo.Presented at the American Diabetes Association 2026 Scientific Sessions (2026) ↗
- [3]Phase 2 dose-finding trial (le Roux et al.)386 adults with obesity or overweight (BMI ≥27), without diabetes · 46 weeksAverage weight loss ranged from 6.2% (0.6 mg) to 14.9% (4.8 mg, highest dose), versus 2.8% with placebo, in the modified intention-to-treat population. At 4.8 mg, 55% of participants lost at least 15% of body weight, versus 6% with placebo. Gastrointestinal disorders were reported in 75% of the combined survodutide group versus 42% with placebo; 25% of the combined survodutide group discontinued treatment because of adverse events.The Lancet Diabetes & Endocrinology (2024) ↗