Reviewed & approved by Dr. Nova Reyes · Last checked 2026-10-25. ← Back to Evidence Library

Survodutide: what the evidence says

Legend: HUMAN data · ANIMAL / LAB data · UNKNOWN · UNVERIFIED: not yet confirmed against a primary source

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What is it?

Survodutide (also called BI 456906) is a lab-made peptide that activates both the glucagon receptor and the GLP-1 receptor. ^{R1, R7} GLP-1 action lowers appetite and blood sugar. Glucagon normally raises blood sugar, but drug makers are testing it alongside GLP-1 because it may increase the energy the body burns and reduce liver fat. Unknown How much the glucagon part adds in people, compared with GLP-1 action alone, has not been tested directly in a published trial.

Mazdutide and retatrutide also act on the glucagon receptor; see the mazdutide page and the retatrutide page.

Does it help weight loss?

All results below are from trials funded by Boehringer Ingelheim. "Treatment-regimen" results count everyone, whether or not they kept taking the drug, which gives a more realistic picture.

• Human Obesity without diabetes (SYNCHRONIZE-1, phase 3): in 725 adults, average weight change was −12.2% and −13.0% on the two survodutide arms vs −5.4% on placebo (treatment-regimen). No deaths were reported. ^R1
• Human Obesity with type 2 diabetes (SYNCHRONIZE-2, phase 3): in 752 adults, weight change was −8.2% and −9.8% vs −3.9% on placebo. People with diabetes usually lose less weight on these drugs. ^R2
• Human Obesity with fatty liver (SYNCHRONIZE-MASLD, phase 3): in 216 adults, weight change was −8.7% vs −1.4% on placebo (treatment-regimen). ^R4
• Human Earlier phase 2 trial: in 386 adults, weight change ranged from −6.2% to −14.9% vs −2.8% on placebo, but only about 60% finished treatment. ^R5
• Caution Company figures can look bigger. Press releases often quote the "efficacy estimand," which assumes everyone kept taking treatment. We report the more cautious treatment-regimen numbers where available. ^{R1, R2, R9}
• Unknown How survodutide compares head-to-head with semaglutide or tirzepatide in people. No published head-to-head trial was found.

Does it help fatty liver disease (MASH)?

MASH (metabolic dysfunction-associated steatohepatitis) is fatty liver with inflammation that can lead to scarring and cirrhosis.

• Human Phase 2 biopsy trial: in 293 adults with MASH and liver scarring, MASH improved without worse scarring in 43% to 62% on survodutide vs 14% on placebo. Scarring improved by at least one stage in 34% to 36% vs 22%. ^R3
• Human SYNCHRONIZE-MASLD (phase 3): 68.5% on survodutide vs 28.6% on placebo had at least a 30% drop in liver fat on MRI (treatment-regimen). This trial measured liver fat, not liver scarring or outcomes, and enrolled only people in the US and Spain. ^R4
• Human Cirrhosis (phase 1, small, open-label): in people with cirrhosis, blood levels were similar to healthy people, and liver fat and stiffness generally fell. Drug-related side effects were common. ^R8
• Unknown Whether survodutide prevents cirrhosis, liver failure or liver cancer. The phase 3 LIVERAGE trials are still recruiting. ^R11

Does it help type 2 diabetes?

• Human Phase 2 trial: in 413 adults on metformin, HbA1c (average blood sugar) fell by up to 1.71 points; one of the lower arms matched open-label semaglutide. The placebo result is not in the part of the abstract we reviewed, and the trial was short. ^R6
• Human SYNCHRONIZE-2: HbA1c fell 0.9 and 0.8 points vs 0.2 on placebo, from a starting level of 7.4%. This was not the trial's main goal. ^R2
• Unknown A phase 3 trial with blood sugar as its main goal is recruiting. ^R11

Is it safe?

What the trials reported:

• Caution Stomach side effects were very common: 80.9% and 89.7% vs 47.9% on placebo in SYNCHRONIZE-1, and 72.8% and 77.7% vs 38.6% in SYNCHRONIZE-2. Most were mild to moderate and happened while the amount was being increased. ^{R1, R2}
• Caution In the MASH phase 2 trial, nausea (66% vs 23%), diarrhea (49% vs 23%) and vomiting (41% vs 4%) were much more common than on placebo. Serious side effects were similar (8% vs 7%). ^R3
• Caution Stopping early: in the phase 2 obesity trial, only about 61% on survodutide finished treatment. ^R5 Boehringer reported that 18% stopped because of stomach side effects in SYNCHRONIZE-2. ^R9 [UNVERIFIED: company figure as reported in news coverage, not in the abstract.]
• Caution GLP-1 class risks: survodutide acts on the GLP-1 receptor, so the risks known for that drug class (pancreatitis, gallbladder disease, rodent thyroid tumors, low blood sugar with insulin or sulfonylureas, older blood-sugar-lowering pills) are reasonable to expect; see the semaglutide page. Unknown The abstracts we reviewed do not report rates of these events.
• Unknown Heart safety: the heart-safety trial has not published results. ^R11
• Unknown Long-term safety and rare harms are unknown.

Compounded and gray-market survodutide: extra risks

• Caution Unregulated "research" vials. Because survodutide is only used inside clinical trials, any vial sold online has no regulatory quality control, and its identity, strength and sterility are unknown.
• Caution Don't stack with other GLP-1 drugs. Taking survodutide with semaglutide, tirzepatide, retatrutide or similar drugs means two drugs acting on the same receptor, which no trial on this page tested. Unknown
• Caution Measuring mistakes. FDA has reported people hospitalized after drawing up too much from multi-injection GLP-1 vials. The same syringe-marking problem applies here. See the section on measuring mistakes on our semaglutide page.

What we don't know

• Unknown What is actually in a given gray-market vial
• Unknown Whether survodutide is safe for the heart, or lowers heart attacks and strokes ^R11
• Unknown Whether it improves liver outcomes, not just liver fat and biopsy scores ^R11
• Unknown Long-term safety, and whether weight comes back after stopping
• Unknown Whether and when Boehringer will file for approval

Is it legal?

Not FDA-approved; no Drugs@FDA record was found (openFDA search, Oct 24, 2026). Boehringer Ingelheim describes survodutide as investigational and says FDA granted it Fast Track (2021) and Breakthrough Therapy (2024) designations for MASH. ^R9 [UNVERIFIED: company source; FDA does not publish these designations.] A designation speeds review; it is not an approval. We found no announced filing in the US or elsewhere. ^{R9, R10} EU, Japan, China: UNVERIFIED not checked against EMA, PMDA or NMPA. WADA: not named on the 2026 Prohibited List; S0 bans at all times any unapproved substance in development that no other section covers, which describes Survodutide ^R12. WADA has not ruled on Survodutide by name. As of Oct 24, 2026.

What's in the vial?

Real survodutide is only available inside clinical trials. We have not found published lab tests of gray-market survodutide. Under the Open Peptide Standard, a GLP-1 vial overfilled by more than 20% is a critical fail (draft threshold). See results at /tests/. A passing test covers one batch, tested on one date. It does not mean the compound itself is safe.

What do users report?

Self-report, not evidence.

Unknown TBD. We'll only list this once we can cite a public source.

Study details

These are doses researchers used, not recommendations. All trials funded by Boehringer Ingelheim. All injections subcutaneous, once weekly unless noted.

R1, R2, R4, R5 Human: Weight trials (SYNCHRONIZE and phase 2)

Study	People	Route	Dose used	Follow-up	Reported	Side effects / dropouts	Citation
SYNCHRONIZE-1 (le Roux 2026), obesity, no diabetes, NCT06066515	725 (241 / 242 vs 242)	Subcutaneous	Survodutide up to 3.6 mg or 6.0 mg once weekly vs placebo + lifestyle	76 wk	−12.2%, −13.0% vs −5.4% (treatment-regimen); ≥5% loss 72.6%, 71.9% vs 46.3%	GI 80.9%, 89.7% vs 47.9%; no deaths	PMID 42253238
SYNCHRONIZE-2 (Wharton 2026), obesity + T2D, NCT06066528	752 (250 / 251 vs 251)	Subcutaneous	Survodutide 3.6 mg or 6.0 mg once weekly vs placebo	76 wk	−8.2%, −9.8% vs −3.9%; ≥5% loss 57.6%, 64.5% vs 35.1%; HbA1c −0.9, −0.8 vs −0.2	GI 72.8%, 77.7% vs 38.6%	PMID 42820639
SYNCHRONIZE-MASLD (Kaplan 2026), obesity + at-risk MASLD, US/Spain	216 (146 vs 70)	Subcutaneous	Survodutide 6.0 mg once weekly vs placebo	48 wk	≥30% liver-fat drop 68.5% vs 28.6%; weight −8.7% vs −1.4% (treatment-regimen); efficacy estimand 84.2% vs 24.3%, −12.2% vs −1.0%	Mostly GI during escalation	PMID 42252333
Phase 2 obesity (le Roux 2024), NCT04667377	386 treated (≈77 per arm)	Subcutaneous	0.6, 2.4, 3.6 or 4.8 mg once weekly vs placebo (20 wk escalation + 26 wk maintenance)	46 wk	−6.2%, −12.5%, −13.2%, −14.9% vs −2.8% (planned treatment)	AEs 91% vs 75%; GI 75% vs 42%; 61% vs 60% completed treatment	PMID 38330987

R3, R6, R8 Human: Liver and diabetes trials

Study	People	Route	Dose used	Follow-up	Reported	Side effects / dropouts	Citation
Phase 2 MASH (Sanyal 2024), biopsy F1–F3, NCT04771273	293	Subcutaneous	2.4, 4.8 or 6.0 mg once weekly vs placebo	48 wk	MASH improvement without fibrosis worsening 47%, 62%, 43% vs 14%; fibrosis ≥1 stage 34%, 36%, 34% vs 22%	Nausea 66% vs 23%; diarrhea 49% vs 23%; vomiting 41% vs 4%; serious AEs 8% vs 7%	PMID 38847460
Phase 2 T2D (Blüher 2024), on metformin, NCT04153929	413	Subcutaneous	Up to 0.3, 0.9, 1.8 or 2.7 mg once weekly, or 1.2 or 1.8 mg twice weekly, vs placebo vs open-label semaglutide up to 1.0 mg	16 wk	HbA1c −0.91 to −1.71 across arms; semaglutide −1.47; weight up to −8.7% vs −5.3% semaglutide	AEs 77.8% vs 52.5% placebo, 52.0% semaglutide	PMID 38095657
Phase 1 cirrhosis (Lawitz 2024), open-label, non-randomized	41 single-dose + 41 multiple-dose	Subcutaneous	Single 0.3 mg; then escalated 0.3 to 6.0 mg weekly over 24 wk + 4 wk	28 wk	Similar PK in cirrhosis vs healthy; liver fat, stiffness, weight generally reduced	Drug-related AEs 82.4% (no cirrhosis) and 87.5% (cirrhosis) in multiple-dose cohorts	PMID 38857788

R7 Background

Zimmermann 2022 (discovery and preclinical pharmacology of BI 456906, GCGR/GLP-1R dual agonist). PMID 36356832

R9–R11 Regulatory and ongoing trials (as of Oct 24, 2026)

• R9 Boehringer Ingelheim press release, SYNCHRONIZE-2 results, Oct 1, 2026: efficacy-estimand weight loss up to 13.1% vs 3.1%; Fast Track and Breakthrough Therapy for MASH; investigational. The 18% GI discontinuation figure is from news coverage of this release. UNVERIFIED Company source.
• R10 Boehringer Ingelheim clinical pipeline (as of August 2026): survodutide in phase 3 for MASH and obesity (source index, browser-verified).
• R11 ClinicalTrials.gov: SYNCHRONIZE-CVOT NCT06077864 (completed, results not found); LIVERAGE NCT06632444 and LIVERAGE-Cirrhosis NCT06632457 (recruiting); T2D trial NCT07754461 (recruiting).
• FDA: no Drugs@FDA record (openFDA query, Oct 24, 2026). EMA, PMDA, NMPA: UNVERIFIED not checked.

Full reference list (all PMIDs verified on PubMed, Oct 24, 2026)

1. le Roux CW, et al. N Engl J Med. 2026;395(8):776-787. doi:10.1056/NEJMoa2600751. PMID 42253238
2. Wharton S, et al. N Engl J Med. 2026 (online Oct 1). doi:10.1056/NEJMoa2607219. PMID 42820639
3. Sanyal AJ, et al. N Engl J Med. 2024;391(4):311-319. doi:10.1056/NEJMoa2401755. PMID 38847460
4. Kaplan LM, et al. Nat Med. 2026;32(8):2948-2958. doi:10.1038/s41591-026-04479-3. PMID 42252333
5. le Roux CW, et al. Lancet Diabetes Endocrinol. 2024;12(3):162-173. doi:10.1016/S2213-8587(23)00356-X. PMID 38330987
6. Blüher M, et al. Diabetologia. 2024;67(3):470-482. doi:10.1007/s00125-023-06053-9. PMID 38095657
7. Zimmermann T, et al. Mol Metab. 2022;66:101633. doi:10.1016/j.molmet.2022.101633. PMID 36356832
8. Lawitz EJ, et al. J Hepatol. 2024;81(5):837-846. doi:10.1016/j.jhep.2024.06.003. PMID 38857788
9. Boehringer Ingelheim. SYNCHRONIZE-2 press release, Oct 1, 2026. https://www.globenewswire.com/news-release/2026/10/01/3372564/0/en/boehringer-ingelheim-s-survodutide-achieves-up-to-13-1-weight-loss-in-new-phase-iii-trial-alongside-significant-improvements-in-glycemic-control-in-people-with-obesity-and-type-2-d.html
10. Boehringer Ingelheim. Clinical pipeline (as of August 2026). https://www.boehringer-ingelheim.com/science-innovation/human-health-innovation/clinical-pipeline
11. ClinicalTrials.gov. NCT06077864, NCT06632444, NCT06632457, NCT07754461.
12. WADA. World Anti-Doping Code International Standard: Prohibited List 2026 (in force Jan 1, 2026). https://www.wada-ama.org/sites/default/files/2025-09/2026list_en_final_clean_september_2025.pdf (text read Oct 24, 2026)

Disclaimer

This page is for education and harm reduction. It is not medical advice and not a recommendation to use survodutide. Please talk to a clinician you trust before making medical decisions, seek care right away for severe stomach pain or repeated vomiting, and report problems to FDA MedWatch (https://www.fda.gov/safety/medwatch).