Survodutide: What It Is, What Phase 3 Showed and When It Could Be Approved

As of October 5, 2026, survodutide (code name BI 456906) is an investigational drug from Boehringer Ingelheim: a once-weekly injection that activates the receptors for two hormones at once, glucagon and GLP-1^[4,12]. It is not approved in any country: it does not appear among the FDA’s novel drug approvals for 2026, and as of September 4 it was not on the European Medicines Agency’s list of applications under review^[23,25]. Its two main phase 3 obesity trials have now been published. In SYNCHRONIZE-1, in people without diabetes, the 6.0 mg dose lowered body weight by an average of 13.0% over 76 weeks, versus 5.4% on placebo, counting every participant whether or not they stayed on treatment^[4].

This is general information, not treatment guidance. If you are considering this or any other medication, talk to your doctor.

What survodutide is

Survodutide is a peptide, a short chain of amino acids, injected under the skin once a week^[4]. It activates two receptors: those for glucagon and GLP-1. That is why it is called a dual agonist^[4,6]. Boehringer Ingelheim holds it under license from Zealand Pharma and is solely responsible for its development and commercialization worldwide^[6,9].

GLP-1 is the hormone behind semaglutide (Ozempic, Wegovy) and tirzepatide (Mounjaro, Zepbound): it curbs appetite and helps control blood sugar. Glucagon acts mainly on the liver. The investigators of the phase 2 liver trial started from the idea that hitting both receptors might work better than GLP-1 alone for MASH^[2]. Zealand sums it up as a drug that could treat obesity while also supporting liver function^[8]. That is a hypothesis still being tested. How each molecule fits into the family is explained in what GLP-1 medications are, and their brand names are in GLP-1 generic and brand names.

In the two large phase 3 obesity trials, doses were stepped up gradually to 3.6 or 6.0 mg a week, with some flexibility allowed for people who did not tolerate a step^[7]. There is no approved dosing schedule, because there is no label.

What phase 2 showed

Phase 2 trials are designed to find the dose, with small groups. Boehringer Ingelheim funded every survodutide trial.

• Obesity without diabetes. 387 adults with a BMI (body mass index, in kg/m²) of 27 or more, over 46 weeks: 20 weeks of dose escalation and 26 of maintenance. Weight fell by 6.2%, 12.5%, 13.2% and 14.9% on 0.6, 2.4, 3.6 and 4.8 mg, versus 2.8% on placebo^[1]. Only 60.4% completed the 46 weeks of treatment, with similar figures in the survodutide and placebo groups^[1].
• Type 2 diabetes. 413 adults on metformin, over 16 weeks, with doses and schedules different from phase 3 (up to 2.7 mg once a week or 1.8 mg twice a week). HbA1c (glycated hemoglobin, a measure of average blood sugar over the past few months) fell by up to 1.71 points, and weight by up to 8.7%^[3].
• Fatty liver disease with inflammation and fibrosis (MASH). 293 adults with biopsy-confirmed MASH and fibrosis stage F1 to F3, over 48 weeks. MASH improved without worsening of fibrosis in 47%, 62% and 43% on 2.4, 4.8 and 6.0 mg, versus 14% on placebo. Fibrosis improved by at least one stage in 34%, 36% and 34%, versus 22%^[2].

Phase 3: the SYNCHRONIZE program

One important detail before the numbers. Zealand’s press releases lead with the efficacy estimand: what would have happened if everyone had stayed on treatment^[8,9]. The papers use the treatment-regimen estimand as their main analysis, which counts every participant whether or not they stayed on treatment^[4,5]. In both trials it also accounts for use of other obesity medications and, in SYNCHRONIZE-1, for slower-than-planned dose escalation^[4,5]. That is why its numbers are smaller. I use the papers’ figures and add the press-release figure where there is one.

Treatment-regimen estimand in the first three rows. Participants analyzed according to the paper; the ClinicalTrials.gov records list 726 for SYNCHRONIZE-1, 755 for SYNCHRONIZE-2 and 218 for SYNCHRONIZE-MASLD^[12,13,17]. SYNCHRONIZE-1 and -2 both had US sites^[12,13].

• SYNCHRONIZE-1. On 3.6 mg, weight fell by 12.2%. At least 5% of body weight was lost by 72.6% on 3.6 mg and 71.9% on 6.0 mg, versus 46.3% on placebo^[4]. With the efficacy estimand, according to Zealand’s release, weight loss reached up to 16.6% (39.2 lb), versus 3.2% on placebo, and up to 85.1% lost at least 5%, versus 38.8%^[8]. Zealand also reports that most of the weight lost was fat: lean mass made up no more than 11.3% of the change at the highest dose^[10]. That figure is not in the paper’s abstract.
• SYNCHRONIZE-2. On 3.6 mg, weight fell by 8.2%. At least 5% was lost by 57.6% and 64.5% on 3.6 and 6.0 mg, versus 35.1% on placebo. From a starting HbA1c of 7.4%, it fell by 0.9 points on 3.6 mg, 0.8 on 6.0 mg and 0.2 on placebo^[5]. With the efficacy estimand, according to Zealand, weight loss reached up to 13.1%, versus 3.1%^[9]. As with the other drugs in the family, people with type 2 diabetes lose less weight.
• SYNCHRONIZE-MASLD. It tested only 6.0 mg. Liver fat, measured by MRI, fell by at least 30% in 68.5% on survodutide, versus 28.6% on placebo; with the efficacy estimand, in 84.2% versus 24.3%^[6]. The authors themselves point to two limitations: it lasted only 48 weeks and enrolled only in the United States and Spain^[6].

What is missing. For the trials in China and Japan, as of October 5, 2026, I have found only design papers on PubMed, not results. The cardiovascular trial is covered further down.

Survodutide and fatty liver disease (MASH)

MASH (metabolic dysfunction-associated steatohepatitis) is the form of fatty liver disease in which, besides fat, there is inflammation and damage, and it can progress to fibrosis (scarring) and cirrhosis.

• Special designations. According to an October 2024 Zealand release, the FDA granted survodutide Breakthrough Therapy designation for adults with non-cirrhotic MASH and moderate or advanced fibrosis^[11]. The EMA added it to PRIME, its priority-medicines scheme, in November 2023 for MASH with fibrosis^[24]. Both speed up development and review; neither is an approval.
• LIVERAGE. About 1,800 adults with MASH and stage F2 or F3 fibrosis. The first part uses a biopsy at 52 weeks to see whether MASH resolves or fibrosis improves. The second follows participants for up to seven years for progression to cirrhosis, transplant and death, among other events. It has sites in more than 30 countries and territories, including the United States, and an estimated primary completion date of December 2031^[15].
• LIVERAGE-Cirrhosis. About 1,590 adults with compensated MASH cirrhosis (no serious complications yet). It measures time to death, transplant or liver decompensation, among other events, with an estimated date of June 2029^[16].

For context, semaglutide already has a phase 3 MASH trial, which I summarize in ESSENCE.

Survodutide vs. retatrutide and tirzepatide

All three are once-weekly injections that act on the GLP-1 receptor, but each adds something different:

Survodutide shares glucagon with retatrutide but has no GIP component. Everything we know about retatrutide is in retatrutide: what it is and where the trials stand.

There is no head-to-head comparison. I have not found any trial on ClinicalTrials.gov that pits survodutide against tirzepatide or retatrutide. SYNCHRONIZE-START, a US study, will enroll people coming off semaglutide or tirzepatide, but everyone will receive survodutide, so it does not compare drugs^[21]. The only data against another GLP-1 drug is a small open-label semaglutide group in the 16-week phase 2 diabetes trial^[3]: not enough to draw conclusions.

Until then, trials can only be set side by side, using the same type of analysis (the treatment-regimen estimand):

The rows can’t be subtracted from each other. The trials ran for different lengths, in different years and countries, and did not define the analysis the same way: SYNCHRONIZE-1 and -2 also count the use of other obesity medications^[4,5]. In that trial the placebo group lost 5.4%, more than in any of the others. Tirzepatide is an approved medicine with an FDA label and years of use; survodutide and retatrutide are not. And survodutide’s case is not only about weight: much of its program focuses on the liver. More trial figures are charted in the trial results chart.

Other drugs in development have their own guides: CagriSema, amycretin and maridebart cafraglutide (MariTide).

Side effects in the trials

Because there is no label, there is no official list of side effects, contraindications or warnings. This is what the papers and press releases report:

• Digestive. The most common in every trial, generally mild to moderate. In SYNCHRONIZE-1 they affected 80.9% on 3.6 mg and 89.7% on 6.0 mg, versus 47.9% on placebo, and no deaths were reported^[4]. In SYNCHRONIZE-2, 72.8% and 77.7%, versus 38.6%^[5].
• Stopping treatment. In SYNCHRONIZE-1, according to Zealand, discontinuations happened mostly during dose escalation^[8]. In SYNCHRONIZE-2, 18% of people on survodutide stopped because of digestive side effects, versus 1.2% on placebo, according to the press release^[9]. That figure is not in the paper’s abstract.
• Phase 2 in MASH. Nausea affected 66% (23% on placebo), diarrhea 49% (23%) and vomiting 41% (4%). Serious adverse events occurred in 8% on survodutide and 7% on placebo^[2].

For digestive symptoms on approved GLP-1 drugs: what to eat with nausea and constipation on GLP-1s.

Is it FDA approved? Regulatory status

The FDA does not publish the applications it is reviewing, so a submission could exist without being public. What I can say is that neither Boehringer nor Zealand has announced a submission or a date in the 2026 releases I have reviewed^[8,9,10].

Can you buy it? Not legally, although it is offered online as a “research peptide.” On August 24, 2026, the FDA sent a warning letter to a company selling, among other things, a product called “Survodutide.” The FDA treats it as an unapproved new drug, even when labeled “for research use” or “not intended for human use,” because the company’s website showed the products were meant for use in people^[26]. The trial results come from a product made by Boehringer and say nothing about a vial bought online. If you have already used one, tell your doctor. For other products sold as alternatives, see natural Ozempic and supplements.

When could it be approved?

There is no date. Its two main obesity trials are published; the cardiovascular trial is not, and Boehringer expects to present those results before the end of 2026^[4,5,9]. A US application would come after that, followed by the FDA review. No filing has been announced.

Meanwhile, the program keeps growing: Boehringer announced four new phase 3 or 3b trials starting in 2026^[10]. ClinicalTrials.gov lists, for example, a type 2 diabetes trial with US sites and an estimated primary completion date of January 2028^[20], and SYNCHRONIZE-HERA, a US trial of about 600 women in perimenopause or postmenopause^[22].

What is still unknown

• Cardiovascular safety. The biggest missing piece. SYNCHRONIZE-CVOT is not designed to show a benefit but to show that survodutide does not raise the risk of cardiovascular death, heart attack, stroke, coronary revascularization or heart failure events^[14]. It finished in June 2026, and Boehringer expects to present the results before the end of the year^[9].
• Long-term liver effects. The biopsy data in MASH come from a 48-week phase 2 trial^[2]. Whether it prevents cirrhosis or transplant is what LIVERAGE and LIVERAGE-Cirrhosis will show, around 2029 to 2031^[15,16].
• What happens after 76 weeks and after stopping treatment. The published papers do not report it^[4,5].
• How it compares with approved drugs. Without head-to-head trials, nobody knows.

Frequently asked questions

What is survodutide and what is it used for?

It is an investigational once-weekly injection from Boehringer Ingelheim that activates the glucagon and GLP-1 receptors^[4]. It is being studied for obesity, type 2 diabetes and fatty liver disease with inflammation (MASH)^[4,5,15]. It is not approved for any of them.

When will survodutide be available?

There is no date. It is not approved anywhere, it is not among the FDA’s 2026 approvals, and Boehringer and Zealand have not announced when they will file^[9,10,25]. The results of its cardiovascular trial are also still pending^[14].

Is survodutide better than Zepbound or retatrutide?

There is no way to know: no trial has compared them directly. The weight figures for each come from trials with different populations, lengths and analyses^[4,27,29]. Also, tirzepatide (Zepbound, Mounjaro) is approved and survodutide is not.

Can you buy survodutide?

Not legally. It is not FDA approved, and the FDA considers products sold online as “Survodutide” to be unapproved drugs^[25,26]. Outside its clinical trials, I have not found any legal way to get it.