Daubert motions deadline passes in the GLP-1 stomach injury MDL

The federal court overseeing thousands of lawsuits over gastrointestinal injuries linked to GLP-1 drugs passed a key procedural milestone on April 28, 2026: the deadline for filing Daubert motions, which are challenges to whether each side's expert witnesses can testify at trial ^[1]. Expert depositions in the litigation, known as MDL 3094, were completed in April 2026, and summary judgment briefing was submitted starting April 30 with full briefing running through July 2026 ^[1].

These are not headline-grabbing events, but in mass litigation they are the gate that decides whether cases reach a jury. A Daubert ruling determines whether a plaintiff's expert may tell jurors that a drug caused a specific injury. If the court excludes key causation experts, large numbers of claims can collapse. If the experts survive, the cases move toward bellwether trials — test cases whose outcomes often shape settlement talks.

Where the litigation stands

MDL 3094 was created by the Judicial Panel on Multidistrict Litigation in February 2024 and sits in the Eastern District of Pennsylvania before Judge Karen S. Marston ^[1]. The defendants are Novo Nordisk, maker of the semaglutide products Ozempic, Wegovy and Rybelsus, and Eli Lilly, maker of the tirzepatide products Mounjaro and Zepbound, along with liraglutide (Victoza, Saxenda) and dulaglutide (Trulicity) ^[1].

The case count has grown steadily. The MDL held 1,331 pending actions in January 2025, 3,546 by April 2026, and 4,022 by September 2026, out of 4,056 total filed ^[1]. About 75% of complaints allege gastroparesis, sometimes called stomach paralysis; roughly 18% allege ileus, and 8% allege gallbladder injuries ^[1].

One reason the expert fight matters so much here is a ruling Judge Marston issued in August 2025. After more than 3,700 pages of briefing and evidentiary hearings, the 78-page decision addressed how gastroparesis must be diagnosed in these cases ^[1]. The court continues to require objective diagnostic testing for gastroparesis claims — generally a gastric emptying study showing more than 10% retention of food at four hours, the standard described by the National Institute of Diabetes and Digestive and Kidney Diseases ^[1].

The underlying science cited in the litigation includes an October 2023 JAMA study by Sodhi and colleagues, which reported that people using GLP-1 drugs for weight loss had 3.67 times the risk of gastroparesis, 4.22 times the risk of bowel obstruction and 9.09 times the risk of pancreatitis compared with another weight-loss drug ^[1]. Plaintiffs argue labels did not adequately warn that delayed stomach emptying — an intended effect of the drugs — could progress to severe, persistent illness ^[1].

Regulators have updated labeling several times. FDA added an ileus warning in September 2023, a pulmonary aspiration warning about anesthesia in January 2025, and in October 2025 added language stating that Ozempic "is not recommended in patients with severe gastroparesis" ^[1].

Why it matters for patients

For people taking or considering these medicines, the litigation itself is not a safety finding. Courts have not ruled on whether the drugs cause gastroparesis, and no verdicts or settlements have been announced as of September 2026 ^[1]. What the case does surface is a set of documented risks already in the prescribing information: ileus, intestinal obstruction, acute pancreatitis, gallbladder disease and aspiration under anesthesia ^[1].

For anyone who believes they were injured, the diagnostic standard is the practical takeaway. Judge Marston's rulings mean claims supported by an objective gastric emptying study are treated differently from those based on symptoms alone ^[1]. Time limits also apply: statutes of limitations generally run two to three years from when an injury is discovered, and they vary by state ^[1].

It is worth noting that this article's available source is a litigation-tracking site that carries an attorney advertising disclaimer ^[1]. Its case counts are drawn from JPML statistics reports, but its trial-timing predictions are estimates, not court orders.

What happens next

Summary judgment briefing was scheduled to run through July 2026, with Daubert motions fully briefed ^[1]. Bellwether trial selection was expected around mid-2026, with the first trials possible in late 2026 at the earliest, depending on how the pending motions are decided ^[1]. Broad settlements are viewed by the tracker as unlikely before late 2027 ^[1].

Separately, vision-loss claims involving NAION were split into their own case, MDL 3163, created in December 2025 and also assigned to Judge Marston; it held about 200 cases as of September 2026 ^[1]. There is no U.S. label warning for NAION ^[1]. Whether any court will rule on causation in either MDL, and when, is not yet known.