Judge Strikes Some Claims and Limits Plaintiffs’ Experts in Ozempic Lawsuits
Philadelphia, August 2025 – In a significant development in the multidistrict litigation (MDL 3094) involving Ozempic and other GLP-1 receptor agonist drugs, U.S. District Judge Karen Spencer Marston has issued a ruling that strikes certain claims and imposes restrictions on plaintiffs’ expert testimonies. The decision, part of the sprawling litigation against drugmakers Novo Nordisk and Eli Lilly, could reshape the trajectory of the lawsuits alleging severe side effects from medications like Ozempic, Wegovy, and Mounjaro.
The Ozempic lawsuits, centralized in the U.S. District Court for the Eastern District of Pennsylvania, primarily focus on claims that these drugs caused severe gastrointestinal issues, such as gastroparesis (stomach paralysis), intestinal blockages, and, more recently, vision loss conditions like non-arteritic anterior ischemic optic neuropathy (NAION). As of August 1, 2025, the MDL encompasses over 2,190 pending cases, with plaintiffs alleging that the manufacturers failed to adequately warn about these risks.
Key Ruling on Claims and Expert Testimony
On August 23, 2024, Judge Marston issued an order addressing critical issues raised by the defendants, Novo Nordisk and Eli Lilly, who sought to streamline the litigation by challenging the admissibility of certain claims and the reliability of plaintiffs’ expert testimonies. The defendants argued that many plaintiffs’ gastroparesis claims lack objective medical evidence, specifically pointing to the absence of gastric emptying studies—a diagnostic test they assert is necessary to confirm the condition. They further contended that no reliable scientific evidence supports claims of injuries beyond those disclosed in the drugs’ FDA-approved labels, which already warn of gastrointestinal side effects like nausea and vomiting.
Judge Marston partially sided with the defendants, ruling that plaintiffs must provide stronger diagnostic evidence to support gastroparesis claims, effectively raising the bar for these allegations. The decision limits the scope of expert testimony, requiring that plaintiffs’ experts adhere to stricter scientific standards under Federal Rule of Evidence 702. This ruling could potentially disqualify claims from plaintiffs who rely solely on symptoms or clinical judgments without formal testing, a move plaintiffs’ attorneys criticized as overly rigid. “Many legitimate diagnoses of gastroparesis are made based on clinical evaluations and patient history,” argued lead plaintiffs’ counsel from Motley Rice. “This standard risks dismissing valid claims prematurely.”
Additionally, the court struck certain secondary claims, such as breach of warranty and fraud, from the master complaint, though failure-to-warn claims—the core of the litigation—remain intact. The defendants’ motion to dismiss other claims, like design defect, was partially granted, narrowing the scope of the litigation as it moves forward.
Implications for the Litigation
The ruling is a pivotal moment in the Ozempic MDL, which has grown significantly since its inception in February 2024. A key evidentiary hearing, known as a Daubert hearing, is scheduled for May 14, 2025, to further scrutinize the admissibility of plaintiffs’ expert testimony on causation. This hearing will determine whether the scientific evidence linking GLP-1 drugs to injuries like gastroparesis and NAION is robust enough to proceed to trial. “If the plaintiffs’ experts survive this challenge, it will strengthen the cases significantly,” said attorney Cameron Stephenson of Levin Papantonio Rafferty, a member of the Plaintiffs’ Executive Committee. “But if not, it could narrow or even dismiss significant portions of the litigation.”
The decision also highlights ongoing tensions in the MDL. Plaintiffs’ attorneys, including those from Seeger Weiss and Morgan & Morgan, argued that ruling on causation and diagnostic standards before full discovery and bellwether trials is premature. They emphasized that MDLs typically address such issues after representative cases provide a fuller factual record. Nevertheless, Judge Marston’s order reflects her intent to manage the sprawling litigation efficiently, addressing cross-cutting issues early to avoid duplicative efforts.
Growing Scope of Allegations
Beyond gastroparesis, the litigation has expanded to include claims of vision loss (NAION) and blood clot-related injuries like deep vein thrombosis (DVT). Plaintiffs recently moved to create a separate “Vision Injury Track” within the MDL to address the growing number of NAION cases, which now exceed 140, according to court filings. A Harvard study published in July 2024 and subsequent research in January 2025 have linked semaglutide, the active ingredient in Ozempic, to an increased risk of NAION, prompting further scrutiny. However, the court declined to include NAION and DVT in the current MDL framework, raising the possibility of a separate MDL for these injuries.
What’s Next?
As the MDL progresses, the focus remains on the discovery phase, with bellwether trial selection expected in the coming months. These early trials will serve as test cases to gauge the strength of plaintiffs’ claims and could influence potential settlement negotiations. No settlements have been reached as of August 2025, and trials are not anticipated until late 2026 or beyond.
For plaintiffs like Monica Church and Bob Tuttle, who spoke to USA TODAY about their life-altering experiences with gastroparesis after taking Ozempic, the ruling introduces new hurdles but does not extinguish hope. “The court’s decision makes it tougher, but we’re fighting for justice,” said Church, who suffered severe nausea and vomiting. Attorneys encourage affected individuals to preserve medical records and document symptoms meticulously to meet the court’s evidentiary standards.
Novo Nordisk and Eli Lilly maintain that their drugs are safe when used as directed and that the risks are adequately disclosed on labels. However, plaintiffs argue that the manufacturers downplayed the severity of side effects, particularly for off-label weight loss use, which has fueled the drugs’ popularity.
A Call to Action
For those who have experienced severe side effects from Ozempic or similar GLP-1 drugs, legal experts recommend consulting with an attorney promptly to assess eligibility within state-specific statutes of limitations. Compensation may cover medical expenses, lost wages, pain and suffering, and punitive damages, depending on the case’s strength.
As the Ozempic litigation continues to unfold, all eyes are on the May 2025 hearing, which could define the future of thousands of claims. For now, Judge Marston’s ruling has set a high bar, challenging plaintiffs to bolster their evidence while keeping the pressure on drugmakers to answer for alleged failures to warn.