Survodutide vs Tirzepatide: differences, evidence and safety

Tirzepatide is an FDA-approved GIP/GLP-1 drug, sold as Zepbound for weight management and sleep apnea and as Mounjaro for type 2 diabetes. Survodutide is an investigational glucagon/GLP-1 drug that has not been approved for use. Both have phase 3 human trials. In separate trials, tirzepatide’s primary result was larger: −20.9% body weight at 72 weeks in SURMOUNT-1 versus −13.0% at 76 weeks for survodutide in SYNCHRONIZE-1. No head-to-head trial was found on ClinicalTrials.gov (searched 2026-10-07).

Item	Survodutide	Tirzepatide
US FDA status	Investigational; not approved for any use; FDA Breakthrough Therapy designation (Sept 2024)	Approved: Mounjaro 2022-05-13; Zepbound 2023-11-08
Compounding	No approved product; FDA has warned sellers of survodutide falsely labeled “for research purposes”	Shortage resolved 2024-12-19; 503A grace ended 2025-02-18, 503B 2025-03-19; 503B bulks exclusion proposed 2026-04-30
WADA 2026	Not named; non-approved substances may fall under S0	Not prohibited; GLP-1 drugs under WADA monitoring
Strongest evidence	Human RCT, phase 3 (n=725, n=752, n=216)	Approved label; phase 3 RCTs (n=2,539, n=938)
Human trials	29 records (searched 2026-10-07)	Phase 3 program incl. SURMOUNT-1 (NCT04184622)
Next regulatory step	No filing date announced (sponsor releases checked 2026-10-07); cardiovascular outcomes results expected later in 2026	No final FDA decision found on the 503B exclusion as of 2026-10-07
Last checked	2026-10-07	2026-10-07

Survodutide vs tirzepatide at a glance

Feature	Survodutide	Tirzepatide
What it is	Investigational weekly injection (Boehringer Ingelheim, with Zealand Pharma)	Approved weekly injection (Eli Lilly): Zepbound, Mounjaro
Class	Dual agonist	Dual agonist
Receptors	Glucagon + GLP-1	GIP + GLP-1
Main research focus	Obesity, MASLD/MASH (fatty liver disease), type 2 diabetes	Type 2 diabetes, obesity, sleep apnea, MASH
Phase 3 weight result, no diabetes	−13.0% at 76 weeks (n=725)	−20.9% at 72 weeks (n=2,539)
Phase 3 weight result, type 2 diabetes	−9.8% at 76 weeks (n=752)	−14.7% at 72 weeks (n=938)
Approval status	Not approved for use	FDA-approved; EU-authorised since 2022
WADA	May fall under S0 (non-approved)	Not prohibited; monitored
Route studied	Subcutaneous injection, weekly	Subcutaneous injection, weekly
Trial length (trials cited here)	46–76 weeks	52–72 weeks
Main safety concerns	GI effects; 18% GI-related stops in one trial; no approved label	Boxed warning (rat thyroid tumors); GI, gallbladder, pancreatitis

Weight figures in both tables come from separate trials and are cross-trial comparisons; the sources are cited in the sections below.

What is survodutide?

Survodutide (BI 456906) is a once-weekly injectable peptide that activates both the glucagon receptor and the GLP-1 receptor, described in its phase 3 obesity paper as “an investigational glucagon receptor-GLP-1 receptor dual agonist”. GLP-1 (glucagon-like peptide-1) is a gut hormone whose receptor is also targeted by tirzepatide and semaglutide. Its liver program rests on the hypothesis, stated in its phase 2 MASH trial, that dual glucagon and GLP-1 action “may be more effective than GLP-1 receptor agonism alone”. It has FDA Fast Track and Breakthrough Therapy designations and EMA PRIME status, which can speed review but are not approvals. It is not obtainable legally outside clinical trials.

What is tirzepatide?

Tirzepatide is a once-weekly injectable that activates the GIP (glucose-dependent insulinotropic polypeptide) and GLP-1 receptors. FDA approved it as Mounjaro for type 2 diabetes in May 2022 and as Zepbound for chronic weight management in November 2023. The Zepbound label also covers moderate to severe obstructive sleep apnea in adults with obesity, and the Mounjaro label added cardiovascular risk reduction in high-risk type 2 diabetes in August 2026. Our retatrutide vs tirzepatide vs semaglutide comparison sets it against the other main incretin drugs.

How they work differently

• Shared target: both activate the GLP-1 receptor; the Zepbound label classes tirzepatide as a “GIP receptor and GLP-1 receptor agonist” (Approved label).
• Survodutide: adds glucagon-receptor activity. In its phase 2 MASH trial, improvement in MASH without worsening fibrosis occurred in 43% to 62% of the survodutide groups versus 14% on placebo (Human RCT, n=293), the main human evidence behind its liver focus.
• Tirzepatide: adds GIP-receptor activity. Its weight effect is established in phase 3 trials such as SURMOUNT-1 (Human RCT, n=2,539) and in its approved label.
• Dose escalation: both are started low and raised. SURMOUNT-1 used a 20-week escalation; SYNCHRONIZE-1’s primary analysis explicitly accounted for “a prolonged dose-escalation period” (Human RCT, n=725).

Evidence head-to-head

Every row below compares separate trials with different populations, durations and analysis methods. These are cross-trial comparisons, not a direct test.

Outcome	Survodutide best evidence	Tirzepatide best evidence
Weight, obesity without diabetes	Human RCT, n=725: −12.2% (3.6 mg), −13.0% (6.0 mg) vs −5.4% placebo, week 76 (SYNCHRONIZE-1)	Human RCT, n=2,539: −15.0% to −20.9% vs −3.1% placebo, week 72 (SURMOUNT-1)
Weight, with type 2 diabetes	Human RCT, n=752: −8.2% and −9.8% vs −3.9%, week 76 (SYNCHRONIZE-2)	Human RCT, n=938: −12.8% and −14.7% vs −3.2%, week 72 (SURMOUNT-2)
Liver fat / MASH	Human RCT phase 3, n=216: ≥30% liver-fat drop in 84.2% vs 24.3% (SYNCHRONIZE-MASLD); phase 2 biopsy RCT, n=293 (Sanyal 2024)	Human RCT phase 2, n=190: MASH resolution 44–62% vs 10% (SYNERGY-NASH)
Blood sugar	Human RCT, n=752: HbA1c −0.9 and −0.8 points vs −0.2 (SYNCHRONIZE-2)	Approved label for type 2 diabetes (Mounjaro)
Sleep apnea	No trial found on ClinicalTrials.gov (searched 2026-10-07)	Approved label; 2 RCTs, n=469 (FDA)
Heart outcomes	Outcomes trial completed, results pending (NCT06077864)	Approved label, high-risk type 2 diabetes (Mounjaro, Aug 2026)
Versus another drug	No head-to-head trial found	Human RCT, n=751: −20.2% vs −13.7% with semaglutide (SURMOUNT-5)

One reason published survodutide numbers vary is the analysis method. SYNCHRONIZE-1’s primary result (−13.0%) uses the “treatment-regimen estimand”, which counts everyone randomized, including people who stopped the drug or used other obesity medicines (Human RCT, n=725). The 16.6% figure in the sponsor’s April 2026 topline release uses the “efficacy estimand”, which estimates the effect in people who stayed on treatment. SURMOUNT-1’s −20.9% is also a treatment-regimen result (Human RCT, n=2,539), so 13.0% versus 20.9% is the closer cross-trial match. The placebo groups also differ: −5.4% in SYNCHRONIZE-1 versus −3.1% in SURMOUNT-1. The same pattern holds in diabetes: the sponsor reports 13.1% for SYNCHRONIZE-2 on the efficacy estimand (sponsor release), while the published treatment-regimen figure is −9.8% (Human RCT, n=752).

Survodutide’s earlier phase 2 obesity trial reported −14.9% at 46 weeks in its highest dose arm (4.8 mg) versus −2.8% on placebo (Human RCT, n=386). The phase 3 trials used a top dose of 6.0 mg and a longer 76-week window.

Which fits which goal?

• Weight loss: tirzepatide has more evidence. It has an approved label, a larger phase 3 program (SURMOUNT-1, n=2,539) and a head-to-head result against semaglutide in SURMOUNT-5. Its cross-trial weight result is also larger than survodutide’s on the comparable analysis.
• Fatty liver disease: survodutide has the more liver-focused program, with a phase 3 liver-fat trial (SYNCHRONIZE-MASLD, n=216) and phase 3 MASH trials still recruiting, including LIVERAGE. Tirzepatide’s MASH biopsy data come from a phase 2 trial (SYNERGY-NASH, n=190) that used a different endpoint (MASH resolution) from survodutide’s phase 2 trial (MASH improvement), so the percentages are not directly comparable. Neither drug’s US label includes MASH as of 2026-10-07.
• Type 2 diabetes, sleep apnea and heart risk: tirzepatide has more evidence, because each of these is an approved use on its Mounjaro or Zepbound label.

These are statements about evidence, not a pick. Only one of the two can be prescribed today, and a clinician is the person to decide whether either fits a given person.

Can they be combined?

No controlled human study has tested survodutide and tirzepatide together. A ClinicalTrials.gov search for both names returned one record (searched 2026-10-07), and it is not a combination study. That record, SYNCHRONIZE-START, is an open-label phase 3b study planned to test starting survodutide fresh or “switching from semaglutide or tirzepatide”, with an estimated 350 participants, an estimated start of 2026-11-07 and primary completion estimated for 2028-06-25. Its primary outcome is percent weight change at week 52.

Safety and regulatory status

Tirzepatide (Approved label). The Zepbound label carries a boxed warning: “In rats, tirzepatide causes thyroid C-cell tumors. It is unknown whether ZEPBOUND causes thyroid C-cell tumors, including medullary thyroid carcinoma (MTC), in humans.” Its warnings also cover severe GI reactions, acute kidney injury from fluid loss, gallbladder disease, pancreatitis, allergic reactions, low blood sugar, diabetic eye complications in type 2 diabetes and aspiration under anesthesia or deep sedation. In SURMOUNT-1, adverse events led to stopping treatment in 4.3% to 7.1% of tirzepatide groups versus 2.6% on placebo (Human RCT, n=2,539).

Survodutide (Human RCT, no approved label). GI symptoms, typically mild to moderate, occurred in 80.9% and 89.7% of the two survodutide groups versus 47.9% on placebo in SYNCHRONIZE-1, with no deaths reported (Human RCT, n=725). In SYNCHRONIZE-2, 18% of people on survodutide stopped treatment because of GI adverse events versus 1.2% on placebo (sponsor release). That figure counts GI-related stops only, while the tirzepatide figure counts all adverse events, so the two are not a clean cross-trial match; the survodutide rate is still 15 times its placebo rate. In the phase 2 MASH trial, nausea affected 66% versus 23% on placebo, and vomiting 41% versus 4% (Human RCT, n=293). Cardiovascular outcome results have not been published as of 2026-10-07, and there is no approved label summarizing long-term risks.

• United States: tirzepatide is FDA-approved; survodutide is not. FDA states it has warned companies that “illegally sold unapproved drugs containing semaglutide, tirzepatide, retatrutide, survodutide or mazdutide” falsely labeled “for research purposes” or “not for human consumption”.
• Compounded tirzepatide: FDA declared the tirzepatide shortage resolved, ending the compounding grace periods in 2025, and on 2026-04-30 proposed excluding tirzepatide from the 503B bulks list. Compounded products are not FDA-approved and are not the same as Zepbound or Mounjaro.
• European Union: tirzepatide (Mounjaro) has been authorised since 15 September 2022; survodutide has EMA PRIME status and no authorisation.
• Sport: USADA says GLP-1s are not prohibited and WADA is monitoring them. Survodutide is not named on the list, but a substance “not approved for clinical use by any governmental regulatory authority” with performance-enhancing potential may be prohibited under S0.

Our overview Are peptides safe? covers the extra risks of unregulated “research” products.

How long do effects take in studies?

The main weight endpoints were measured late: 72 weeks for tirzepatide in SURMOUNT-1, after a 20-week dose escalation (Human RCT, n=2,539), and 76 weeks for survodutide in SYNCHRONIZE-1 and SYNCHRONIZE-2 (Human RCT, n=725). Liver results were read earlier: survodutide’s liver-fat endpoint at 48 weeks (Human RCT, n=216) and tirzepatide’s MASH biopsy endpoint at 52 weeks (Human RCT, n=190). The SYNCHRONIZE-MASLD authors list the 48-week length as a limitation.