Mounjaro and Zepbound Lawsuits: What Is Actually Alleged, and Where the Cases Stand

If you search for “Mounjaro lawsuit,” most of what comes back is advertising. Law firm pages are built to collect your contact details, and they are not required to be careful about the difference between an allegation, a filed case and a finding by a court.

This page tries to be careful about exactly that. It sets out which lawsuits exist, which drugs each one actually names, what is alleged, what Eli Lilly says in its own filings, and what has been decided. As of September 14, 2026, the honest answer to “has anyone won?” is: nobody has, on either side.

Nothing here is legal advice or medical advice.

What is MDL 3094, and is Mounjaro part of it?

MDL 3094 is the federal multidistrict litigation over gastrointestinal injuries allegedly caused by GLP-1 receptor agonist drugs. It was created by the Judicial Panel on Multidistrict Litigation on February 2, 2024, consolidating the federal GLP-1 gastrointestinal injury cases then pending across the country into the Eastern District of Pennsylvania. It is now before Judge Karen S. Marston [1][5].

A multidistrict litigation is not a class action. Each case stays its own lawsuit with its own plaintiff and its own facts. What gets consolidated is the shared pretrial work: document discovery, expert testimony, and the legal questions that apply to everyone.

The court’s own public description of MDL 3094 names the drugs this way: “Ozempic, Wegovy, and Rybelsus, which are manufactured by the Novo Nordisk defendants, and Trulicity and Mounjaro, which are manufactured by Eli Lilly and Company” [1].

So yes, Mounjaro is in it. Zepbound is not named in the court’s own description, although Eli Lilly’s own briefing identifies Trulicity, Mounjaro and Zepbound as its GLP-1 medicines at issue in the litigation [4]. If you read that a Zepbound MDL exists as a separate thing, it does not.

The court’s description also records the key point about liability plainly: after summarizing the allegations, it states that “the Novo Nordisk defendants and Eli Lilly and Company deny these allegations” [1].

How many cases are there?

As of the Judicial Panel’s September 1, 2026 count, MDL 3094 had 4,022 actions pending, out of 4,056 filed in total [5]. That figure covers all defendants in the MDL, Novo Nordisk and Eli Lilly together. The public dockets do not break the total out by drug.

What injuries do the Mounjaro lawsuits allege?

The JPML’s own framing of the shared questions is whether the manufacturers knew or should have known that their GLP-1 products “can cause gastroparesis and other gastrointestinal injuries,” whether they adequately warned patients or prescribing physicians, and whether they made false, misleading or incomplete safety representations [1].

The injuries most often alleged are:

• Gastroparesis — the stomach emptying so slowly that food sits in it, causing persistent nausea, vomiting, early fullness and weight problems.
• Ileus — the bowel stopping its normal muscular movement.
• Intestinal obstruction and severe constipation with fecal impaction.
• Gallbladder disease, including gallstones and gallbladder removal.
• Pancreatitis.

Case trackers maintained by law firms estimate that roughly 75% of MDL 3094 complaints allege gastroparesis, about 18% allege ileus and about 8% allege gallbladder injuries. Those are estimates from trackers, not figures published by the court, and should be read as approximations [1].

Two of those items are on the tirzepatide labels in a limited way. Ileus, intestinal obstruction and severe constipation with fecal impaction all appear in the postmarketing experience section of both the Mounjaro and Zepbound labels, which means they come from spontaneous reports and the label says their frequency cannot be reliably estimated [10]. Gastroparesis is not listed as an adverse reaction at all; instead the labels say tirzepatide is not recommended in people with severe gastroparesis [10]. That gap between what is on the label and what plaintiffs say should have been on it is the heart of the dispute.

What has the court actually decided so far?

Three things are worth knowing, because they are real rulings rather than allegations.

August 15, 2025 — the gastroparesis diagnosis order. In a cross-cutting issue ruling, Judge Marston held that any plaintiff claiming gastroparesis must show the diagnosis rests on a properly performed gastric emptying study, and excluded two plaintiff diagnostic experts. That raised the evidentiary floor for the single largest category of claims [1].

December 12, 2024 — blood clot claims kept out. The JPML declined to add deep vein thrombosis and venous thromboembolism claims to the MDL [1].

December 15, 2025 — vision loss cases separated. The JPML declined to fold the NAION vision-loss cases into MDL 3094, creating a separate MDL instead (see below) [3][9].

Everything else is still pending.

What is happening in September 2026?

From September 14 through September 18, 2026, Judge Marston is holding a Rule 702 evidentiary hearing — often called a Daubert hearing — on cross-cutting issues 2 and 3. The court’s own MDL page states those dates [2].

This is the pivotal event in the litigation so far. A Rule 702 hearing decides whether the plaintiffs’ general causation experts are allowed to testify at all: that is, whether there is scientifically admissible evidence that these drugs can cause the injuries alleged. If the answer is no, the claims in that category cannot reach a jury, regardless of how sympathetic any individual case is. If the answer is yes, the litigation moves toward bellwether trials.

As of September 14, 2026, no ruling had issued.

What does Eli Lilly argue?

Lilly’s May 2026 roadmap brief lays out nine numbered motions, and it is unusually direct about the company’s theory of the case [4].

The three pillars:

1. The labels adequately warned prescribers. Under the learned intermediary doctrine used in most states, a manufacturer’s duty to warn runs to the prescribing physician, not directly to the patient.

2. Preemption. Lilly argues that where the FDA considered and rejected additional warnings, a state-law claim that the company should have added them anyway is preempted by federal law. Its brief applies this argument to gastroparesis claims and, in its ninth motion, to claims involving malnutrition, micronutrient deficiency, Wernicke’s encephalopathy and muscle wasting.

3. No admissible general causation evidence. This is what the September 2026 hearing addresses.

Lilly’s brief also sets out which time periods its expert’s opinions cover for each injury: for Mounjaro, ileus from 2017/2018 to November 2022, and intestinal obstruction and constipation including fecal impaction from 2017/2018 to March 2026 [4].

It is worth being explicit about what that document is. It is a defendant’s characterization of its own motions, filed by a party with an interest in the outcome. The court had not ruled on any of it as of September 14, 2026.

Is there a Zepbound or Mounjaro vision loss lawsuit?

There is a federal vision-loss MDL, and its origin is unusual: Eli Lilly asked for it.

On August 19, 2025, Lilly moved the JPML to centralize the NAION cases — non-arteritic anterior ischemic optic neuropathy, a sudden loss of vision caused by reduced blood flow to the optic nerve — either before Judge Marston or by folding them into MDL 3094. On December 15, 2025 the Panel centralized 21 actions as MDL 3163 before Judge Marston, but declined to merge them into MDL 3094, reasoning that a separate docket would make coordination and case tracking cleaner [3][9].

Here is the part that most coverage gets wrong. The court’s own MDL 3163 page describes the drugs at issue as “Ozempic, Wegovy, and Saxenda, which are manufactured by the Novo Nordisk Defendants, and Trulicity, which is manufactured by Eli Lilly and Company” [2]. The JPML transfer order uses the same four drugs [3]. Mounjaro and Zepbound are not named in either primary court description.

That matches the science. NAION does not appear anywhere on the Mounjaro or Zepbound labels. Reporting-database studies do find an optic neuropathy signal for tirzepatide, but a much weaker one than for semaglutide; one 2026 comparative analysis of the FDA’s spontaneous reporting system put semaglutide’s reporting odds ratio at 94.45 against tirzepatide’s at 2.94.

As of September 1, 2026 MDL 3163 had 216 cases pending [5]. It is in early case management, with a Science Day held June 2, 2026 and a July 2026 order authorizing early motion practice on general causation and preemption [3]. No dismissals, no causation rulings, no trial date, no settlement.

What other lawsuits involve Eli Lilly and tirzepatide?

Three categories, none of which are personal injury cases.

The Texas attorney general’s kickback suit

In August 2025 the Texas attorney general, with co-plaintiff Health Choice Alliance, sued Eli Lilly under the Texas Health Care Program Fraud Prevention Act. The complaint alleges that two Lilly programs — a “Free Nurse Program” said to provide in-kind services such as injection training, and a “Support Services Program” said to handle reimbursement paperwork — amounted to illegal inducements for providers to prescribe Lilly drugs, including Mounjaro and Zepbound. The state seeks more than $1 million in damages, civil penalties and a permanent injunction, and names fourteen Lilly medicines [6].

Lilly denies the allegations and has said it will defend vigorously. It has pointed out that the same co-plaintiff brought similar claims against Lilly in 2017 over other products; that case was dismissed and the Fifth Circuit upheld the dismissal in 2021 [11].

This is a case about marketing and reimbursement practices, not about whether the drugs hurt anyone.

FDA warning letters over promotion

On September 9, 2025 the FDA’s Office of Prescription Drug Promotion issued warning letters to Eli Lilly over direct-to-consumer promotional videos, finding they were false or misleading and therefore misbranded the drugs [7].

The most notable one concerned an ABC and Hulu primetime special. The FDA said that statements by a paid consultant — that pancreatitis, gallbladder complications and thyroid cancer concerns had “really not been shown in human studies” and carried risk “less than 1%” — misleadingly minimized the serious risks of Zepbound and Mounjaro, including the boxed warning. The agency also said the MEN 2 contraindication had been omitted, along with risks including severe gastrointestinal disease, acute kidney injury, hypersensitivity reactions, hypoglycemia, suicidal behavior and ideation, and diabetic retinopathy complications [7].

Lilly said it had no editorial control over the interviews used. Novo Nordisk received a parallel letter over the same program.

A warning letter is a regulatory finding about advertising. It is not a finding that anyone was injured, and it is not part of the MDL. But it is a rare document in which the FDA itself lists, in its own words, the full risk set it considers material for these two drugs.

Lilly suing compounders and telehealth companies

This is the litigation where Eli Lilly is the plaintiff. Since September 2023 the company has sued med spas, wellness centers, compounding pharmacies and telehealth platforms over compounded tirzepatide. In April 2025 it sued four telehealth companies in California federal courts, alleging deception about untested, unapproved products including oral tablets and drops, and formulations mixed with additives such as niacinamide, glycine and l-arginine [8].

Lilly’s safety-framed allegations are worth separating from its commercial ones. The safety claims are that no clinical trial has evaluated oral tirzepatide or tirzepatide mixed with additives, and that Lilly has found compounded products containing bacteria, high impurity levels, wrong colors, a different chemical structure, and in at least one instance nothing but sugar alcohol [8]. Those are allegations by a company with an obvious commercial interest, and the courts have not found them proven.

The results have been mixed. In February 2026 the Central District of California dismissed Lilly’s amended complaint against one telehealth defendant, an earlier ruling in that case having found no proximate causation because the products require a prescription. In April 2026 the Northern District of California largely denied dismissal in a different case, allowing false-advertising claims to proceed.

What has not been decided?

It is worth stating the negatives plainly, because they are the part the advertising leaves out. As of September 14, 2026:

• No court has found Eli Lilly liable for any tirzepatide injury.
• No bellwether trial has been held or scheduled in either MDL.
• No settlement exists in either MDL.
• No ruling has issued on the September 2026 Rule 702 motions.
• No dollar figure has been established for any claim. Settlement “estimates” published by law firms are projections used in marketing, not offers.

What if you think you have been harmed?

Two things are separate, and it helps to keep them separate.

The medical question — whether your symptoms are related to a medication, and what to do about them — belongs with a healthcare provider. Gastroparesis in particular has a specific diagnostic test, the gastric emptying study, and the MDL court’s own August 2025 order made that test the standard for claims in this litigation.

The legal question belongs with a lawyer you choose, not one who found you. Deadlines for filing vary by state, and the fact that a case has been filed does not mean it will succeed.

Sources

1. MDL 3094 In Re: GLP-1 Receptor Agonists Products Liability Litigation (GI Injuries) — Eastern District of Pennsylvania
2. MDL 3163 In Re: GLP-1 Receptor Agonists NAION Products Liability Litigation — Eastern District of Pennsylvania
3. JPML transfer order creating MDL 3163, December 2025
4. Eli Lilly Rule 702 and summary judgment roadmap brief, May 2026
5. JPML pending MDL dockets
6. Texas attorney general announcement of suit against Eli Lilly, August 2025
7. FDA warning letter to Eli Lilly, MARCS-CMS 716485, September 9, 2025
8. Eli Lilly sues compounded Mounjaro and Zepbound providers — CNBC
9. GLP-1 blindness lawsuits become second mass litigation — Reuters
10. ZEPBOUND (tirzepatide) prescribing information — DailyMed
11. Eli Lilly pledges vigorous defense against Texas AG suit — Fierce Pharma