Survodutide is investigational and has no approved label anywhere. This page summarises adverse events as published in its clinical trials. It is educational and does not substitute for professional medical evaluation.
Overview
Survodutide's adverse-event profile is dominated by gastrointestinal symptoms, and in its trials those symptoms were the norm rather than the exception. In phase 3, gastrointestinal events occurred in 80.9% of participants on 3.6 mg and 89.7% on 6.0 mg, against 47.9% on placebo. They were generally described as mild to moderate and clustered during dose escalation — but a figure near 90% is not a footnote.
The numbers, trial by trial
SYNCHRONIZE-1 (phase 3, n=725, 76 weeks) reported gastrointestinal symptoms as the most common adverse events, typically mild to moderate, at 80.9% (3.6 mg), 89.7% (6.0 mg), and 47.9% (placebo). No deaths were reported (NEJM 2026; PMID 42253238).
The phase 2 MASH trial (n=293, 48 weeks) broke the category down by symptom:
| Event | Survodutide (pooled) | Placebo |
|---|---|---|
| Nausea | 66% | 23% |
| Diarrhea | 49% | 23% |
| Vomiting | 41% | 4% |
| Serious adverse events | 8% | 7% |
Those figures come from NEJM 2024; PMID 38847460. The serious-adverse-event rate being essentially identical to placebo is the more reassuring line in that table, and it sits alongside a nausea rate near two thirds.
In the phase 2 obesity trial (n=386, 46 weeks), adverse events of any kind occurred in 91% of survodutide recipients versus 75% on placebo, primarily gastrointestinal in 75% versus 42% (Lancet Diabetes Endocrinol 2024; PMID 38330987).
What completion rates reveal
Adverse-event tables record what happened; completion rates record what people were willing to tolerate. In the phase 2 obesity trial, only 233 of 386 participants — 60.4% — completed the 46-week treatment period, including 61% of those on survodutide and 60% of those on placebo.
The near-identical placebo figure matters: it suggests that trial burden and the fast 20-week escalation schedule, not the drug alone, drove much of the attrition. It also means the reported weight-loss numbers describe a population from which four in ten participants dropped out, which is the kind of context that rarely survives into a headline.
What is not yet known
- Long-term safety. The longest published trial ran 76 weeks. Rare events and cumulative effects are not detectable at that scale.
- Cardiovascular outcomes. No published outcome trial establishes benefit or harm; baseline characteristics for the cardiovascular outcomes trial have been published, but not results.
- Population reach. SYNCHRONIZE-MASLD recruited only in the United States and Spain, a limitation its authors state directly (Nature Medicine 2026; PMID 42252333).
- Unregulated material. No licensed survodutide product exists in any market. Anything sold under that name is research-grade material of unverified identity, purity, and concentration, and none of the safety data above describes it.