2026-08-18 · survodutide, BI 456906, boehringer ingelheim, zealand pharma, GLP-1, glucagon, MASH, fatty liver, next-generation obesity drug, pipeline

What is survodutide and how does it work?

Survodutide (development code BI 456906) is a once-weekly subcutaneous peptide that activates two receptors in one molecule — the GLP-1 receptor and the glucagon receptor. It was discovered by Zealand Pharma and is being developed to Phase 3 by Boehringer Ingelheim. The GLP-1 arm suppresses appetite, slows gastric emptying, and improves insulin secretion — the same mechanism that drives Ozempic and Wegovy. The glucagon arm drives hepatic β-oxidation, mobilizes liver fat, and raises resting energy expenditure by roughly 5 percent, adding a metabolic lever that pure GLP-1 drugs do not have. Doses studied in Phase 2 were 0.6 mg, 2.4 mg, 3.6 mg, and 4.8 mg weekly.

How much weight do people lose on survodutide?

In the Le Roux 2024 Phase 2b obesity trial (n=387, 46 weeks) reported in the Lancet, mean total body weight loss was roughly 2.3 percent on placebo, 6.2 percent at 0.6 mg, 12.5 percent at 2.4 mg, 15.7 percent at 3.6 mg, and roughly 18.7 percent at the 4.8 mg weekly dose. About 40 percent of the 4.8 mg arm achieved at least 15 percent loss, and waist circumference dropped by roughly 14.2 cm at the top dose. Notably, the weight-loss curve had not plateaued at 46 weeks — the definitive plateau will be characterized in the Phase 3 SYNCHRONIZE obesity program, whose primary readouts are expected in mid-2026.

Is survodutide approved in the United States?

No. Survodutide is not FDA-approved and is not commercially available in the United States as of August 2026. It received FDA Breakthrough Therapy Designation in February 2024 for the treatment of MASH with F2 or F3 fibrosis, based on the Phase 2 MASH data — the first drug in the GLP-1 / glucagon dual-agonist class to receive that status — but Breakthrough Designation is a review-acceleration tool, not an approval. The pivotal Phase 3 SYNCHRONIZE obesity program and the LIVERAGE MASH program are still enrolling and reading out. Realistic US availability for the obesity indication is 2028 at the earliest, and for the MASH indication early 2028 or later.

How is survodutide different from Ozempic, Zepbound, or Rezdiffra?

Ozempic and Wegovy (semaglutide) are pure GLP-1 receptor agonists. Zepbound and Mounjaro (tirzepatide) are GLP-1 / GIP dual agonists. Survodutide is a GLP-1 / glucagon dual agonist — a different second receptor entirely, chosen for its hepatic-fat and energy-expenditure effects. Rezdiffra (resmetirom) is a thyroid hormone receptor-beta agonist approved specifically for MASH; it does not produce meaningful weight loss on its own. Survodutide is the first drug in development targeting both indications from a single molecule, and it is the only pipeline drug in the GLP-1 / glucagon dual class to hold FDA Breakthrough status for MASH with fibrosis.

Does survodutide treat fatty liver (MASH)?

In the Sanyal 2024 Phase 2 MASH trial (n=293, 48 weeks) reported in the New England Journal of Medicine, survodutide at the 4.8 mg dose produced MASH resolution without fibrosis worsening in 63 percent of patients versus 14 percent on placebo, and fibrosis improvement of at least one stage in 65 percent of patients versus 26 percent on placebo. Weight loss was a secondary endpoint at roughly 14.9 percent. Those Phase 2 numbers are the basis for the FDA Breakthrough Therapy Designation. Definitive MASH efficacy will be tested in the Phase 3 LIVERAGE program, whose readouts are expected in 2027.

What are the side effects of survodutide?

The Phase 2b and Phase 2 MASH safety picture is a class-typical GLP-1 tolerability profile plus two glucagon-attributable signals. Nausea occurred in roughly 42 to 50 percent of patients, vomiting in 20 to 25 percent, and diarrhea in 18 to 22 percent — mostly during titration. Discontinuation for gastrointestinal intolerance was about 7 percent at the 4.8 mg dose. Glucagon-arm signals were a heart-rate increase of 3 to 5 beats per minute, a transient rise in liver enzymes in the first 8 weeks that usually normalized, and an unexpected LDL-cholesterol rise of roughly 8 mg/dL that is being followed in Phase 3. No thyroid C-cell tumor signal or excess pancreatitis above the GLP-1-class baseline has been reported to date.

When will survodutide be available in the US?

Realistically 2028 at the earliest for obesity, and early 2028 or later for MASH — assuming the Phase 3 programs read out on plan and the FDA review runs on standard cadence. SYNCHRONIZE-1 obesity primary readout is expected in mid-2026, with three additional Phase 3 obesity trials and a cardiovascular outcomes trial reading out through 2028. The MASH Phase 3 program (LIVERAGE-1 and LIVERAGE-2, combined enrolment ~1,600) reads out in 2027. A standard 10-month FDA review after a 2027 NDA filing would put the earliest approval in late 2028, with commercial pharmacy availability shortly after. There is no legitimate US access route before that.

Can I get survodutide through a compounding pharmacy?

No. Two facts govern this. Survodutide has never been on the FDA drug-shortage list — the trigger that briefly opened 503A and 503B compounding for semaglutide and tirzepatide during their 2022 to 2024 shortages. And the active pharmaceutical ingredient is proprietary to Boehringer Ingelheim and Zealand Pharma; no US compounding pharmacy has legal access to it. Any product sold in 2026 as 'survodutide' or 'BI 456906' by a telehealth peptide clinic, gray-market compounder, or overseas pharmacy is either counterfeit or an unrelated peptide, not the drug from the Le Roux 2024 or Sanyal 2024 trials. FDA compounding enforcement actions in 2024 and 2025 targeted this exact pattern of gray-market GLP-1 marketing.

Survodutide for Weight Loss and MASH: −18.7% at 46 Weeks, FDA Breakthrough Status, and the Boehringer Pipeline

Survodutide is not FDA-approved and is not sold anywhere in the United States as of August 2026 — no legitimate pharmacy, telehealth clinic, or compounding operation can supply it. It is an investigational once-weekly injection developed by Boehringer Ingelheim and Zealand Pharma, with development code BI 456906. The molecule is a dual GLP-1 / glucagon receptor agonist and is the only drug in that class to hold FDA Breakthrough Therapy Designation for MASH with F2 or F3 fibrosis (granted February 2024). Phase 3 obesity and MASH programs are ongoing, with the first pivotal readout expected in mid-2026. Any product marketed today as “survodutide” from an overseas pharmacy, telehealth peptide site, or gray-market compounder is either counterfeit or research-chemical peptide — see compounded semaglutide and tirzepatide safety for the analytical picture on what actually shows up in those vials.

This page explains what survodutide is, what the Le Roux 2024 Phase 2b obesity trial and Sanyal 2024 Phase 2 MASH trial showed, how it compares to the drugs already on pharmacy shelves (tirzepatide, semaglutide, Rezdiffra) and to the other next-generation candidates mapped in the next generation weight loss drugs pillar, and what the realistic 2026 read is for US patients.

What survodutide is

Survodutide (BI 456906) is a once-weekly subcutaneous peptide that activates two receptors in one molecule: the GLP-1 receptor and the glucagon receptor. The molecule was discovered by Zealand Pharma and licensed to Boehringer Ingelheim, which has taken it into Phase 3 for both obesity and MASH. Doses studied in the pivotal Phase 2 program were 0.6 mg, 2.4 mg, 3.6 mg, and 4.8 mg weekly, with 4.8 mg as the target obesity dose carried into Phase 3.

The receptor pairing separates survodutide from every currently-approved US drug. Semaglutide (Wegovy, Ozempic) is a pure GLP-1 agonist. Tirzepatide (Zepbound, Mounjaro) is a GLP-1 / GIP dual agonist. Survodutide adds the glucagon arm — glucagon’s traditional role of mobilizing hepatic glucose and fat, harnessed in the context of GLP-1 co-signaling to add a resting-energy-expenditure lever and a direct liver-fat-mobilization effect. The mechanism was formally characterized in Zimmermann 2023 (Journal of Medicinal Chemistry), the primary preclinical paper on BI 456906.

How survodutide compares to other next-generation obesity drugs

The comparison below sets survodutide against the other next-generation obesity molecules covered on this site. Only mazdutide (Signifor) is approved for obesity anywhere in the world today; survodutide, retatrutide, MariTide, and CagriSema are all still investigational.

Two things to read from that table. First, survodutide is the only pipeline drug in the GLP-1 / glucagon class with FDA Breakthrough Therapy Designation for MASH with fibrosis — the mechanism-specific milestone that separates it from mazdutide (also GLP-1 / glucagon) and from the pure-obesity pipeline of retatrutide and CagriSema. Second, on pure weight-loss magnitude, survodutide’s ~18.7% Phase 2b number sits between semaglutide and tirzepatide and ahead of mazdutide, but behind retatrutide’s ~24.2% triple-agonist signal. The distinctive value proposition is the dual obesity-and-MASH indication from a single molecule.

Phase 2b obesity trial (Le Roux 2024)

Le Roux CW et al. (Lancet 2024) is the pivotal Phase 2b obesity trial that anchored the Phase 3 SYNCHRONIZE dose selection. It enrolled 387 adults with obesity (BMI ≥27 with at least one comorbidity, or BMI ≥30) and randomized them to survodutide 0.6 mg, 2.4 mg, 3.6 mg, or 4.8 mg weekly, or matching placebo, on top of lifestyle counseling, for 46 weeks.

Waist circumference dropped by roughly 14.2 cm at the 4.8 mg dose. Critically, the weight-loss curve had not plateaued at 46 weeks — the trajectory suggests further loss with longer treatment, and Phase 3 SYNCHRONIZE will characterize where the plateau actually lands.

Two honest limitations on how to read Le Roux 2024. First, 46 weeks is short for an obesity trial by 2026 standards — SURMOUNT-1 ran 72 weeks and STEP-1 ran 68 weeks. Second, this is Phase 2b, not the pivotal Phase 3; the definitive numbers, cardiovascular safety signal, and durability past one year will come from SYNCHRONIZE-1.

Phase 2 MASH trial (Sanyal 2024)

Sanyal AJ et al. (New England Journal of Medicine 2024) is the Phase 2 MASH trial that produced the FDA Breakthrough Therapy Designation. It enrolled 293 adults with biopsy-confirmed MASH and F1 through F3 fibrosis, randomized them across placebo and survodutide arms up to 4.8 mg weekly, and repeated the paired liver biopsy at 48 weeks — the FDA-accepted histologic endpoint.

Those Phase 2 numbers are the largest reported in a paired-biopsy MASH trial to date across the incretin and dual-agonist class, and they are the basis on which the FDA granted Breakthrough Therapy Designation in February 2024 for MASH with F2 or F3 fibrosis — the first GLP-1 / glucagon dual to reach that milestone. Definitive Phase 3 histologic confirmation will come from the LIVERAGE program.

Phase 3 program (SYNCHRONIZE and LIVERAGE)

The Phase 3 program is the largest ongoing GLP-1 / glucagon dual program in the field, spanning obesity, T2D, and MASH.

No specific Phase 3 weight-loss number is public until the SYNCHRONIZE-1 readout — Le Roux 2024’s ~18.7% at 46 weeks is the current best estimate but is not the pivotal number.

How survodutide works (balanced GLP-1 / glucagon co-agonism)

The two-arm mechanism is what separates survodutide from every currently-approved US drug — and from other dual and triple agonists in the pipeline.

GLP-1 arm. Same as semaglutide: activates the GLP-1 receptor on pancreatic beta-cells, on hypothalamic satiety circuits, and on gastric and intestinal smooth muscle. Downstream effects are glucose-dependent insulin secretion, delayed gastric emptying, and appetite suppression — the mechanism that produces the shared class effect across every GLP-1-based drug.

Glucagon arm. Activates the glucagon receptor on hepatocytes. In isolation, glucagon raises fasting blood sugar. In co-agonism with GLP-1, the net glucose effect is neutral or favorable — GLP-1’s insulinotropic action offsets the glucagon-driven hepatic glucose output. What is left is a distinct set of glucagon-driven effects: increased resting energy expenditure (roughly 5 percent) through hepatic β-oxidation, mobilization of hepatic fat (the ~45% MRI-PDFF reduction at 24 weeks in the MASH substudy), and modest lipid and adiposity redistribution.

Compared to mazdutide, which is also a GLP-1 / glucagon dual, survodutide has a more balanced receptor-affinity profile — mazdutide is more GLP-1-weighted, survodutide more glucagon-weighted. That balance is the reason survodutide’s liver-fat and fibrosis numbers in the Sanyal 2024 MASH trial exceed mazdutide’s DREAMS-2 substudy figures at matched exposure. Cegla 2021 (Nature Reviews Endocrinology) is the canonical mechanism reference for the class; Nahra 2022 (Diabetes Care) reported the cotadutide dataset that first established the class-wide pattern of liver-fat mobilization.

Safety and side effects

The Le Roux 2024 and Sanyal 2024 safety pictures are class-typical GLP-1 tolerability, titration-limited, plus three glucagon-attributable signals.

No thyroid C-cell tumor signal, no clinically significant pancreatitis excess above GLP-1 baseline, and no gallbladder signal beyond the class baseline have been reported. The LDL-C rise is the atypical finding — most GLP-1 / glucagon dual agonists in development (cotadutide, mazdutide, and pemvidutide) have shown neutral or favorable LDL effects (Altimmune’s IMPACT Phase 2 actually reported an LDL and ApoB reduction), so the survodutide signal is being characterized in the SYNCHRONIZE-CVOT cardiovascular outcomes trial.

The MASH angle: why survodutide’s liver-fat data matters for obesity readers

Roughly 40 to 70 percent of adults with obesity have some degree of steatotic liver disease, and MASH — the inflammatory stage — is now among the leading causes of liver transplantation in the United States. Existing obesity drugs already show MASH benefit: semaglutide reported significant MASH resolution in the ESSENCE trial (2024, NEJM), and tirzepatide reported both MASH and preliminary fibrosis benefit in SYNERGY-NASH. But survodutide’s Phase 2 MASH numbers (63% MASH resolution, 65% fibrosis improvement at 48 weeks) exceed what has been reported for either drug at the same paired-biopsy endpoint. That is the mechanism-specific advantage of the glucagon arm — hepatic-fat mobilization on top of the weight-loss-mediated MASH benefit.

The clinical implication is that survodutide is on track to be the first drug approved for both chronic weight management and MASH from a single label — a meaningful simplification for the very large population that carries both diagnoses. For the current MASH treatment landscape, see resmetirom (Rezdiffra) for MASH and fatty liver and weight loss.

Where survodutide will fit in the future obesity market

Three patient profiles are the most likely first-line candidates when survodutide reaches US pharmacies.

What survodutide does not do (yet)

Explicit list, because the noise around next-generation drugs consistently overstates what a Breakthrough Designation means for a US patient:

• Not FDA-approved. Not now, and realistically not until late 2028 at the earliest for the obesity indication.
• Not compoundable. No drug-shortage listing, no legal 503A or 503B pathway, no US pharmacy access to the active pharmaceutical ingredient.
• Not covered by US insurance. Coverage requires FDA approval as a first condition.
• Not head-to-head against tirzepatide, mazdutide, or retatrutide. No direct comparison trials exist yet; the planned Phase 3b program includes head-to-head comparators but data are years out.
• Not backed by cardiovascular outcomes data. SYNCHRONIZE-CVOT reads out in 2028; until then, cardiovascular benefit is inferred, not proven.
• LDL signal not yet resolved. The unusual Phase 2b LDL-cholesterol rise needs Phase 3 clarification before US labeling.

Practical read for US patients in 2026

If you are asking about survodutide because a clinician mentioned it or because the FDA Breakthrough Designation press cycle reached you, the honest read has three parts.

First: survodutide is a serious next-generation option. The Phase 2 obesity and MASH numbers are competitive with or ahead of anything else in the dual-agonist class, and the FDA Breakthrough Designation for MASH with fibrosis is a genuine regulatory milestone — not a marketing label.

Second: there is no US access route today, and none will exist until at least late 2028. The pivotal Phase 3 obesity readout is mid-2026 and the FDA NDA is expected in 2027; a standard 10-month review puts earliest approval in late 2028. Any product marketed today as “survodutide” or “BI 456906” is not the Boehringer / Zealand molecule from the Le Roux 2024 or Sanyal 2024 trials. The exact peptide sequence is proprietary and cannot be legitimately compounded. Attempting to source it from a grey-market or overseas channel is not a workaround — sterility, dose accuracy, and identity are unverifiable.

Third: the nearest US-available options with proven MASH benefit are already on pharmacy shelves. For the currently approved MASH drug, see resmetirom (Rezdiffra) for MASH. For GLP-1 drugs with MASH data, see semaglutide (ESSENCE) and tirzepatide (SYNERGY-NASH). For the broader obesity plus MASH context, see fatty liver and weight loss. For the full pipeline map, see next generation weight loss drugs.

The correct action for a US patient with obesity and MASH who is a candidate for GLP-1 pharmacotherapy is to start on an FDA-approved option now if clinically appropriate — and to switch or add survodutide when, and only when, it reaches US pharmacies through the legitimate FDA channel.