More than 4,000 actions alleging gastrointestinal injuries associated with GLP-1-based medicines are pending in a US federal multidistrict litigation (MDL). According to the latest statistics published by the US Judicial Panel on Multidistrict Litigation (JPML), 4,082 actions were pending in MDL No. 3094 as of 2 November 2026, while the total number of actions historically recorded in the MDL was 4,196.
The litigation involves Novo Nordisk and Eli Lilly, whose medicines are the subject of claims alleging that their use caused serious gastrointestinal disorders and that manufacturers failed to provide adequate warnings about potential risks.
Which medicines are involved?
The litigation is coordinated by the US District Court for the Eastern District of Pennsylvania under MDL No. 3094. Multidistrict litigation (MDL) allows cases involving common factual questions to be coordinated before a single court for pretrial proceedings, without automatically merging individual claims into a single lawsuit.
The court’s memorandum of August 2025 identifies eight medicines as being at issues in the proceeding:
- Novo Nordisk: Ozempic, Wegovy and Rybelsus (semaglutide), as well as Victoza and Saxenda (liraglutide).
- Eli Lilly: Trulicity (dulaglutide), Mounjaro and Zepbound (tirzepatide).
The litigation concerns GLP-1 receptor agonists and dual GLP-1/GIP receptor agonists.
What complications are alleged?
The claims primarily concern injuries affecting the gastrointestinal system. The injuries alleged in the court proceedings include:
- gastroparesis, a disorder characterised by delayed gastric emptying
- ileus and intestinal obstruction
- intestinal pseudo-obstruction
- other gastrointestinal injuries, including claims involving gallbladder damage
Plaintiffs allege that the manufacturers failed to adequately inform patients and healthcare professionals about the potential risks associated with these medicines. The claims also raise questions about product labelling, safety warnings and the communication of risk information.
These allegations have not been established as findings of fact. The presence of a gastrointestinal condition in an individual patient does not, by itself, demonstrate that treatment with a GLP-1 medicine caused it. Establishing causation remains a central issue in the proceedings.
Manufacturers dispute the allegations
Both Novo Nordisk and Eli Lilly deny the allegations, according to the official court information.
The litigation involves several distinct legal questions, including the adequacy of product warnings, alleged design defects, manufacturing-related negligence and whether the reported injuries can be causally linked to treatment.
One important aspect concerns the medical evidence required to establish a diagnosis of gastroparesis. In August 2025, the court ruled on the admissibility of expert opinions concerning the diagnosis of drug-induced gastroparesis. In an accompanying order, it required plaintiffs claiming gastroparesis to support the diagnosis with a properly performed gastric emptying study (scintigraphy, breath test or wireless motility capsule).
The proceedings subsequently moved to further evidentiary disputes. In September 2026, the court held a Rule 702 evidentiary hearing on expert evidence relating to additional cross-cutting issues. On 8 October 2026, the court scheduled closing arguments on the pending motions for 13 October 2026.
These proceedings are significant because the admissibility and reliability of expert evidence may influence how plaintiffs can establish general causation in the litigation.
What do current FDA warnings say?
The litigation also draws attention to the distinction between recognised adverse reactions and the specific injuries alleged by plaintiffs.
The current US prescribing information for Ozempic identifies gastrointestinal adverse reactions, including severe reactions, and states that the medicine is not recommended for patients with severe gastroparesis.
The prescribing information for Mounjaro contains a similar warning. Both labels also describe gastrointestinal adverse reactions observed in clinical trials and reported post-marketing.
However, the existence of these warnings does not automatically resolve the legal questions concerning whether particular injuries were caused by treatment or whether manufacturers fulfilled all applicable obligations to communicate risks.
The case therefore raises broader questions about the relationship between clinical safety evidence, post-marketing surveillance, product labelling and the legal standards applied when assessing alleged medicine-related injuries.
A separate litigation concerns visual impairment
The gastrointestinal proceedings are not the only federal litigation involving GLP-1 medicines.
A separate proceeding, MDL No. 3163, concerns allegations of non-arteritic anterior ischaemic optic neuropathy (NAION) associated with these medicines.
According to the same JPML report dated 2 November 2026, this separate proceeding included 278 pending actions.
The two proceedings address different categories of alleged injury and should not be treated as a single body of claims.
As both cases continue, the litigation places questions of medicine safety, pharmacovigilance, risk communication and product liability under close scrutiny. However, the pending claims should not be interpreted as proof of a causal relationship between GLP-1 treatment and the injuries alleged, or as a determination of manufacturers’ legal liability.
