Tirzepatide Lawsuits

Eli Lilly makes tirzepatide. It’s the active ingredient in its brand-name medications, Mounjaro and Zepbound. The U.S. Food and Drug Administration (FDA) approved Mounjaro to treat type 2 diabetes in 2022. In 2023, it approved Zepbound as a weight-loss drug for obese and overweight people with at least one related health condition (high cholesterol, hypertension or type 2 diabetes).

Eli Lilly is facing litigation involving GLP-1 receptor agonist (GLP-1 RA) drugs. Eli Lilly lawsuits also involve its GLP-1 drug Trulicity®, made with the active ingredient dulaglutide.

People are filing personal injury claims and pharmaceutical product liability claims against Eli Lilly over tirzepatide. Plaintiffs allege that tirzepatide caused them to suffer serious side effects and injuries, including severe gastrointestinal side effects and vision loss.

The lawsuits also allege that Eli Lilly did not adequately disclose side effects and risks to healthcare providers or the public.

Tirzepatide lawsuits involve the brand-name diabetes and weight loss drugs Mounjaro and Zepbound.

Mounjaro lawsuits

Mounjaro is Eli Lilly’s tirzepatide drug that is FDA-approved to treat type 2 diabetes. Mounjaro lawsuits include personal injury claims and product liability claims. They allege that Eli Lilly:

• Failed to warn users and prescribing physicians about the severe health risks associated with tirzepatide. A failure-to-warn lawsuit can help encourage proper drug labeling, allowing future patients to be aware of all associated risks. This helps people make fully informed decisions about their healthcare.
• Portrayed tirzepatide medications as safe both on labels and via advertising. None of Eli Lilly’s marketing warned consumers about the risk of certain severe conditions after taking the drug.
• Marketed tirzepatide medications aggressively for weight loss. Marketing downplayed the drug’s symptoms as “mild” or “temporary” in order to make them more broadly appealing to a wider group of people.

Mounjaro lawsuits are part of broader GLP-1 litigation, including claims against Novo Nordisk. Novo Nordisk drugs named in the suits include Ozempic®, Wegovy®, and Rybelsus®, all made with the active ingredient semaglutide. Other Novo Nordisk drugs named are Saxenda® and Victoza® (liraglutide).

Zepbound lawsuits

Zepbound is Eli Lilly’s tirzepatide drug approved for chronic weight management in overweight or obese adults with a related health condition. Zepbound lawsuits make similar personal injury and product liability claims as cases involving Mounjaro. They are also part of broader GLP-1 litigation.

Tirzepatide lawsuits claim that the medication causes serious side effects. Injuries alleged in the litigation include:

• Acute gallbladder disease
• Acute kidney injury (AKI)
• Blood clots and deep vein thrombosis (DVT)
• Diabetic retinopathy complications (in patients with type 2 diabetes mellitus)
• Gastroparesis (stomach paralysis)
• Ileus (a condition that prevents food from passing through the intestines, potentially leading to an intestinal blockage/bowel obstruction)
• Necrotizing pancreatitis
• Non-arteritic anterior ischemic optic neuropathy (NAION), leading to vision loss and blindness
• Severe allergic reactions
• Severe vomiting and diarrhea, potentially leading to dehydration and malnutrition
• Thyroid C-cell tumors

The most significant tirzepatide lawsuit update is that claims involving gastrointestinal injuries and vision loss have been divided into two separate federal MDLs. Judge Karen S. Marston is presiding over both in the U.S. District Court for the Eastern District of Pennsylvania.

Gastrointestinal litigation

The first GLP-1 MDL, formed in 2024, consolidates claims involving gastrointestinal injuries. It’s called In re: Glucagon-like Peptide-1 Receptor Agonists (GLP-1 RAs) Products Liability Litigation, MDL No. 3094. As of Aug. 3, 2026, the MDL had 3,928 pending actions. Motley Rice attorney Jonathan Orent serves as co-lead counsel for the litigation and attorney Sara Couch serves on the Plaintiffs’ Executive Committee as Chair of the Marketing Discovery Committee.

As of yet, there are no settlements in this litigation. The case is still in the pre-trial stages.

Vision-loss litigation

The vision-loss MDL was created in December 2025 when Judge Marston ordered these cases be separated from the ones involving gastrointestinal injuries. Its name is In re: Glucagon-like Peptide-1 Receptor Agonists (GLP-1 RAs) Non-Arteritic Anterior Ischemic Optic Neuropathy (NAION) Products Liability Litigation, MDL 3163. It addresses claims involving NAION, which causes vision loss. As of August 2026, it had 200 pending actions.

This MDL is also in the pre-trial phase. The court is currently engaged in early discovery and motions. On June 2, 2026, Judge Marston held a Science Day for the case. Both sides had the chance to present the court with educational information and medical studies related to NAION, GPL-1s and eye conditions. Motley Rice attorney Jonathan Orent serves as co-lead counsel for the litigation and attorney Grace Chandler serves on the Plaintiffs’ Executive Committee.

To qualify for a tirzepatide lawsuit, you must have proof that you took a tirzepatide medication manufactured by Eli Lilly. You must also show that taking the drug caused you to experience a severe side effect that Eli Lilly did not adequately warn the public about.

You may be eligible for a GPL-1 MDL if you have evidence of the following:

• Drug use: You were prescribed Zepbound, Mounjaro or another GLP-1 by a doctor. You used the medication as directed.
• Injury: You suffered a serious drug injury, such as gastroparesis or NAION.
• Medical diagnosis: You have medical records proving your injury. This includes diagnostic test results, such as blood work, MRIs, CT scans and vision tests.
• Timing: You developed your condition while taking or shortly after taking tirzepatide or another GLP-1.
• Treatment: Your injury resulted in surgery, hospitalization or other significant medical treatment. This led to damages for medical bills, lost wages, pain and suffering.

Evidence of the above doesn’t necessarily guarantee you can take legal action. There are claim-specific requirements. There are also filing deadlines known as statutes of limitations that vary from state to state. A Motley Rice tirzepatide lawyer could review your claim and discuss your potential lawsuit eligibility.

Motley Rice medical attorneys have represented thousands of patients seriously injured by dangerous prescription and over-the-counter drugs, including lawsuits involving diabetes and weight loss medications. If you believe tirzepatide or a similar drug made you sick or harmed your health, our attorneys have the resources needed to investigate your potential claim thoroughly.

A Motley Rice lawyer can help you by:

• Building your case: Filing a tirzepatide lawsuit is complex. A knowledgeable lawyer can help you by identifying what is necessary to build a claim.
• Gathering evidence: We can help you understand what documentation is needed for your claim and request documents from medical providers for you.
• Investigating your harm: Our team can analyze medical costs, lost wages and other damages for which you may be eligible.
• Litigating your claim: Our team can litigate the claim in court on your behalf.

Read more on our medical drug litigation experience.

Do not stop taking a prescribed medication without first consulting with your doctor. Discontinuing a prescribed medication without your doctor’s advice can result in injury or death. Zepbound, Mounjaro, Trulicity, Ozempic, Rybelsus, Wegovy, Victoza and Saxenda remain approved by the U.S. Food and Drug Administration.