Up to 16.6% at which dose?

SYNCHRONIZE-1 randomised 3.6 mg and 6.0 mg over 76 weeks, and the released figure is phrased as up to 16.6%, which points at the higher dose without giving a separate mean for each one. That phrasing is a feature of a topline release rather than a full publication. The per-dose breakdown is one of the things to look for when the complete data appear.

If it raises energy expenditure, would some of the weight lost be muscle?

The published release does not say, and independent coverage flagged body composition as one of the questions it left open. Glucagon-receptor agonism raises exactly that question, because increased energy expenditure does not specify which tissue is being drawn down. Nothing in SYNCHRONIZE-1 as reported settles it either way.

Two receptors instead of one. Shouldn't that mean more weight loss?

Survodutide's up to 16.6% at 76 weeks sits below single-target results published for other agents, so the second receptor did not translate into a bigger headline number. Mechanism counts targets, and trials count outcomes, and those are separate things. Where the glucagon component does show up distinctly is the liver-fat data.

Survodutide: GLP-1/Glucagon Dual Agonist

What this page establishes

SYNCHRONIZE-1 enrolled 725 adults with obesity or overweight without type 2 diabetes, randomised to placebo or survodutide 3.6 mg or 6.0 mg for 76 weeks.
Weight loss reached up to 16.6% at 76 weeks vs 3.2% placebo (p<0.0001); 85.1% achieved >=5% loss vs 38.8%.
Up to 84.2% of survodutide participants had at least a 30% relative reduction in liver fat vs 24.3% on placebo.
Topline SYNCHRONIZE-1 results were released 28 April 2026, with full data at the ADA Scientific Sessions in June 2026.

Quick answers

Up to 16.6% at which dose?
SYNCHRONIZE-1 randomised 3.6 mg and 6.0 mg over 76 weeks, and the released figure is phrased as up to 16.6%, which points at the higher dose without giving a separate mean for each one.
Read the full answer
That phrasing is a feature of a topline release rather than a full publication. The per-dose breakdown is one of the things to look for when the complete data appear.
If it raises energy expenditure, would some of the weight lost be muscle?
The published release does not say, and independent coverage flagged body composition as one of the questions it left open.
Read the full answer
Glucagon-receptor agonism raises exactly that question, because increased energy expenditure does not specify which tissue is being drawn down. Nothing in SYNCHRONIZE-1 as reported settles it either way.
Two receptors instead of one. Shouldn't that mean more weight loss?
Survodutide's up to 16.6% at 76 weeks sits below single-target results published for other agents, so the second receptor did not translate into a bigger headline number.
Read the full answer
Mechanism counts targets, and trials count outcomes, and those are separate things. Where the glucagon component does show up distinctly is the liver-fat data.

Survodutide produced up to 16.6% mean weight loss at 76 weeks in SYNCHRONIZE-1, which puts it below retatrutide and CagriSema on the headline number and roughly in line with semaglutide. The interesting data are elsewhere. Up to 84.2% of participants achieved at least a 30% relative reduction in liver fat, against 24.3% on placebo, and Boehringer Ingelheim has run a separate programme in metabolic dysfunction-associated steatotic liver disease. Survodutide is investigational and is not approved anywhere as of 23 August 2026.

What survodutide is

Survodutide is a once-weekly injectable peptide that activates both the glucagon receptor and the GLP-1 receptor. GLP-1 agonism drives appetite suppression and slowed gastric emptying. Glucagon-receptor agonism is associated with increased energy expenditure and with direct effects on the liver, which is where this molecule's distinctive data sit.

It shares its dual mechanism with mazdutide, though the two are separate molecules with separate trial programmes and populations, and one of them is approved in China while the other is not approved anywhere.

SYNCHRONIZE-1

SYNCHRONIZE-1 enrolled 725 adults with obesity, or overweight, without type 2 diabetes, randomised to placebo or survodutide at 3.6 mg or 6.0 mg for 76 weeks. Topline results were released on 28 April 2026, with full data presented at the ADA Scientific Sessions in June 2026.

The responder figure is the one worth holding onto. 85.1% of treated participants lost at least 5% of body weight against 38.8% on placebo, which says most people in the trial got a clinically meaningful result rather than a small group getting a very large one and dragging the mean up. That distribution matters more to an individual reader than the headline mean does.

Weight loss up to 16.6% at 76 weeks versus 3.2% on placebo (p<0.0001)
85.1% of treated participants lost at least 5% of body weight, versus 38.8% on placebo
Up to 84.2% achieved at least a 30% relative reduction in liver fat, versus 24.3% on placebo

The liver-fat data

The liver-fat result is the reason to pay attention to survodutide rather than filing it as a weaker retatrutide. A 30% relative reduction in liver fat is a clinically meaningful threshold in steatotic liver disease, and 84.2% of participants reaching it in an obesity trial, not a liver trial, is a substantial signal.

SYNCHRONIZE-MASLD tested survodutide directly in adults with overweight or obesity and metabolic dysfunction-associated steatotic liver disease with inflammation and/or fibrosis. That programme is where the hepatic question gets answered properly, and readers should look for its published results rather than extrapolating from the obesity trial.

Liver fat is a marker, not an outcome Reducing liver fat on imaging is not the same as resolving steatohepatitis or reversing fibrosis, which are the endpoints that matter clinically. The SYNCHRONIZE-1 result is a strong marker signal from an obesity trial. Treat it as a reason to read the MASLD programme, not as a substitute for it.

What the topline release left open

Independent coverage of the phase 3 release flagged unanswered questions, including body-composition detail. That matters for any drug with a glucagon component, because increased energy expenditure raises the question of what tissue the weight came from.

Glucagon-receptor agonism also raises heart-rate and hepatic-parameter questions as a class consideration. Those are the specific things to look for in the full publications rather than in a press release.

Where it sits in the pipeline

On headline weight loss, survodutide is fourth of the four late-stage candidates. Retatrutide reported 28.3% at 80 weeks on 12 mg in TRIUMPH-1. CagriSema reported 22.7% at 68 weeks in REDEFINE-1. Mazdutide, the other GLP-1 and glucagon dual agonist, reported about 20% on 9 mg in a phase 3 of Chinese adults and is approved in China. Survodutide reported up to 16.6% at 76 weeks in SYNCHRONIZE-1.

Why 16.6% is not automatically worse than 22.5%

Tirzepatide reached 22.5% at 72 weeks on 15 mg in SURMOUNT-1. Survodutide reached 16.6% at 76 weeks in SYNCHRONIZE-1. Those figures come from different trials with different populations, different comparators and different placebo responses, and no head-to-head trial has been run.

The placebo arms alone illustrate the problem. SURMOUNT-1 placebo lost 2.4%. SYNCHRONIZE-1 placebo lost 3.2%. Placebo response varies with trial design, lifestyle support and population, and it moves the apparent effect size of the active arm. Ranking drugs off a table of headline percentages produces confident answers that the underlying evidence does not support.

Development and regulatory status

Survodutide is in phase 3 development with Boehringer Ingelheim and has no marketing authorisation from any major regulator as of 23 August 2026. There is no prescription route and no compounding route. It is investigational only, and material sold online under its name is not the trial drug.

Not medical advice Educational content only, with no dosing, sourcing or preparation guidance. Survodutide is investigational and has no legal human-use route as of 23 August 2026. Any treatment decision belongs with a licensed prescriber.

The evidence, one row per claim

Claim	Tier	Source
SYNCHRONIZE-1 enrolled 725 adults with obesity or overweight without type 2 diabetes, randomised to placebo or survodutide 3.6 mg or 6.0 mg for 76 weeks.	established	Boehringer Ingelheim SYNCHRONIZE-1 topline press release, 28 April 2026 (Internet Archive snapshot)
Weight loss reached up to 16.6% at 76 weeks vs 3.2% placebo (p<0.0001); 85.1% achieved >=5% loss vs 38.8%.	established	Boehringer Ingelheim SYNCHRONIZE-1 topline press release, 28 April 2026 (Internet Archive snapshot)
Up to 84.2% of survodutide participants had at least a 30% relative reduction in liver fat vs 24.3% on placebo.	established	Boehringer Ingelheim
Topline SYNCHRONIZE-1 results were released 28 April 2026, with full data at the ADA Scientific Sessions in June 2026.	established	Boehringer Ingelheim SYNCHRONIZE-1 topline press release, 28 April 2026 (Internet Archive snapshot)
SYNCHRONIZE-MASLD tested survodutide in overweight/obese adults with metabolic dysfunction-associated steatotic liver disease with inflammation and/or fibrosis.	emerging	Boehringer Ingelheim
Independent coverage noted the phase 3 release left key questions unanswered, including body-composition detail.	emerging	Fierce Biotech
Tirzepatide: 2.5 mg initiation then 5 / 10 / 15 mg weekly maintenance; 16.0% / (10 mg intermediate) / 22.5% mean loss at 72 weeks (SURMOUNT-1).	established	Eli Lilly / NEJM

Sources

Where this comes from

Researched and edited by Thomas Prommer — biohacker, performance athlete, data enthusiast and health coach.

Every number on this page traces to a named source. There are 7 sourced claims below the fold, each with the document it came from.

Sources consulted: Boehringer Ingelheim SYNCHRONIZE-1 topline press release, Boehringer Ingelheim, Fierce Biotech, Eli Lilly / NEJM.

Not clinically reviewed. This page was researched and written against primary regulatory and trial sources, and no clinician has checked it.

Sources last read 2026-08-23.

Keep reading

Educational content, reviewed 2026-08-23. Not medical advice, not a prescription, and not a substitute for a clinician who knows your history. Doses named here are label schedules or doses used in named trials, never a recommendation to you.

Survodutide: GLP-1/Glucagon Dual Agonist and the Liver-Fat Angle