Survodutide

Survodutide (BI 456906) is a once-weekly injected peptide that activates the GLP-1 and glucagon receptors. Boehringer Ingelheim develops it under a license from Zealand Pharma, for obesity and for fatty liver disease (MASH). It is in phase 3 and not approved anywhere.

No. It is investigational. The FDA gave it Breakthrough Therapy designation for MASH with moderate or advanced fibrosis in 2024, which speeds review but is not an approval. FDA warning letters in 2024 and 2026 called survodutide sold online an unapproved new drug.

SYNCHRONIZE-1 and -2 stepped people up to 3.6 mg or 6.0 mg once a week and held that dose to week 76. Phase 2 tested 0.6 to 4.8 mg for obesity and 2.4 to 6.0 mg for MASH. The MASLD trial used 6.0 mg with a floor of 2.4 mg if people needed to step down.

The Chinese phase 3 trial wrote it out: 0.3 mg, then 0.6, 1.2, 2.4, 3.6 and 4.8 mg, moving up every 4 weeks. Phase 2 climbed every 2 weeks over 20 weeks, which caused more stomach trouble, so phase 3 slowed down and allowed pauses and one-step dose cuts.

In SYNCHRONIZE-1 (no diabetes), average loss at 76 weeks was 12.2% at 3.6 mg and 13.0% at 6.0 mg, vs 5.4% on placebo, counting everyone who started. For people who stayed on treatment it was up to 16.6% vs 3.2%. With type 2 diabetes (SYNCHRONIZE-2) it was 8.2% and 9.8% vs 3.9%.

Guides use 1 or 2 mL. With 2 mL you get 5 mg/mL, so each unit on a U-100 insulin syringe is 50 mcg. With 1 mL you get 10 mg/mL, so each unit is 100 mcg. More water makes small doses easier to measure.

Stomach and gut effects: nausea, vomiting, diarrhea and constipation, mostly mild to moderate and mostly during the dose climb. In SYNCHRONIZE-1 they hit 80.9% at 3.6 mg and 89.7% at 6.0 mg vs 47.9% on placebo. Heart rate rises a few beats per minute and blood pressure tends to fall.

In SYNCHRONIZE-MASLD, 23.3% stopped for an adverse event vs 10.0% on placebo, mostly for stomach effects. In the 16-week diabetes trial it was 12.9% of everyone treated. The slower phase 3 schedules were designed to cut this.

We found no published human half-life figure. One guide gives an estimate of about 6 to 7 days, which fits once-weekly dosing. The question comes up on r/Survodutide without a sourced answer.

No trial compares them. Retatrutide hits three receptors (GLP-1, GIP, glucagon) and posted 24.2% at 48 weeks in phase 2; survodutide hits two and posted 16.6% at 76 weeks in phase 3 for people who stayed on it. Cross-trial numbers like these mislead easily.

Tirzepatide pairs GLP-1 with GIP and is FDA approved. Survodutide pairs GLP-1 with glucagon and adds a stronger liver fat effect, but it is not approved. No head-to-head trial exists. People stalled on tirzepatide ask about switching on r/Survodutide; there is no data on how to switch.

In the phase 2 MASH trial, MASH improved without worse fibrosis in 47% to 62% of people on survodutide vs 14% on placebo. In SYNCHRONIZE-MASLD, 84.2% of people on 6.0 mg cut liver fat by at least 30%, vs 24.3% on placebo (efficacy estimand). Phase 3 MASH trials are running.

r/Survodutide is small and most posts are about stacking it with tirzepatide after a stall. Posters start at 0.3 or 0.6 mg, the first trial steps, and report settling around 1 to 2.8 mg. Some report vomiting or diarrhea near 2.4 mg on top of tirzepatide. Others ask whether grey-market vials are worth it vs retatrutide, and people who struggled with nausea or anxiety on other drugs ask about it on r/Peptides.

It is not named on the WADA 2026 list. Class S0 bans drugs still in clinical development with no approval from any health authority, and survodutide has none, but WADA has not confirmed that S0 covers it. Tested athletes should check with their anti-doping organization.

As a once-weekly injection under the skin from a pre-filled syringe. Trials never mixed powder with water; that only happens with grey-market research vials.