The Eli Lilly tirzepatide lawsuits fall into two very different piles. On one side, Lilly is the plaintiff, suing compounding pharmacies, dose-splitting clinics, and telehealth platforms that keep selling alternatives to Mounjaro and Zepbound after the FDA declared the shortage over. On the other, Lilly is the defendant in multidistrict litigation brought by thousands of patients who say tirzepatide caused gastroparesis, intestinal obstruction, pancreatitis, gallbladder disease, or sudden vision loss. Both sides of the docket are active in 2026.
Why the Litigation Wave Started
Tirzepatide is the active ingredient in Mounjaro (type 2 diabetes) and Zepbound (obesity). While both drugs sat on the FDA shortage list, compounding pharmacies were allowed to produce copies under sections 503A and 503B of the Federal Food, Drug, and Cosmetic Act.
On October 2, 2024, the FDA removed tirzepatide from the shortage list. After a brief remand, the agency reaffirmed that conclusion in a Declaratory Order issued December 19, 2024, finding that Lilly’s supply met or exceeded demand across all strengths.1McDermott Will & Emery. Tirzepatide Shortage Resolved State-licensed 503A pharmacies had until February 18, 2025, and federally registered 503B outsourcing facilities had until March 19, 2025, to stop producing tirzepatide copies.2FDA. FDA Clarifies Policies for Compounders as National GLP-1 Supply Begins to Stabilize Anyone still producing after those dates faced FDA enforcement plus private suits from Lilly.
The Shortage Case: Outsourcing Facilities Association v. FDA
The compounding industry’s main challenge is Outsourcing Facilities Association v. FDA, Case No. 4:24-cv-00953 in the Northern District of Texas, filed October 7, 2024, by the OFA and FarmaKeio. The plaintiffs asked the court to force tirzepatide back onto the shortage list. Lilly intervened as a defendant in January 2025.3Fierce Pharma. Lilly Looks to Wade Into Legal Fracas Between FDA and Compounders Following End of Tirzepatide Shortage
On March 5, 2025, U.S. District Judge Mark Pittman denied the compounders’ preliminary injunction, ordering 503A pharmacies to stop producing tirzepatide immediately and holding 503B facilities to the March 19 deadline.4Fierce Pharma. Texas Court Decision Prevents Compounders From Producing Knockoffs of Eli Lilly Tirzepatide Drugs Final judgment upholding the FDA came on May 13, 2025.5BioSpace. Lilly Wins Court Battle Against Compounders as Judge Backs FDA
The OFA appealed to the Fifth Circuit (Case No. 25-10600), filing its opening brief on July 30, 2025. The appeal was still pending as of early 2026.6Courthouse News Service. OFA v. FDA Appellants Brief Until the Fifth Circuit rules, the FDA’s determination that tirzepatide is no longer in shortage stands.
Lilly’s Suits Against Compounding Pharmacies
Lilly has largely sidestepped patent claims against compounders. Its theory is built on the Lanham Act, the federal trademark and false-advertising statute, combined with state consumer-protection laws.
Empower Pharmacy
Lilly sued the Houston-based 503B facility Empower Pharmacy on April 1, 2025, in the District of New Jersey, alleging it was mass-producing “knockoff” tirzepatide. Lilly singled out Empower’s “Tirzepatide ODT” orally dissolving tablet, calling it an “untested knockoff” and a “mass testing experiment” on consumers.7Houston Public Media. Eli Lilly Sues Houston-Based Compounding Pharmacy Over Alleged Knockoff Obesity, Diabetes Drugs Empower responded that the case was “not about safety” but “about control.” The day after the suit was filed, the FDA issued Warning Letter #700964 to Empower’s Houston facility, citing unsanitary manufacturing conditions, inadequate environmental monitoring, and labeling deficiencies.8FDA. Empower Clinic Services LLC dba Empower Pharmacy Warning Letter
Lilly voluntarily dismissed the New Jersey case on July 25, 2025, and refiled the same day in the Southern District of Texas (Case No. 4:25-cv-03464).9Buchanan Ingersoll & Rooney. Major Update on GLP-1 Litigation Involving Compounding Pharmacies In late April 2026, a federal judge dismissed part of Lilly’s complaint against Empower while letting other claims proceed.10Endpoints News. Court Dismisses Part of Lilly Lawsuit Against Empower; Some Claims Can Proceed
Strive Pharmacy
Also on April 1, 2025, Lilly sued Strive Pharmacy in the District of Delaware, alleging Lanham Act false advertising and deceptive trade practices under Delaware law. The complaint says Strive marketed its compounded tirzepatide as “customized” for individual patients while actually selling a single standardized formulation.11CNBC. Eli Lilly Sues Strive and Empower Over Compounded Tirzepatide Strive called the suit “Big Pharma overstepping” and said it would defend the case. A Delaware court filing shows the case is now working through personal-jurisdiction questions.12U.S. District Court for the District of Delaware. Eli Lilly and Co. v. Strive Pharmacy LLC
Premier Weight Loss (Dose-Splitting)
Premier Weight Loss, an Indianapolis clinic, is accused of something different from compounding: cracking open factory-sealed Mounjaro and Zepbound auto-injector pens, transferring the medication into third-party insulin syringes, and reselling the split doses as “authentic” and “FDA-approved” (Case No. 1:25-cv-00664, S.D. Ind.). Lilly argues that practice destroys sterility and constitutes trademark infringement and false advertising.13GovInfo. Eli Lilly and Co. v. Premier Weight Loss
Premier counterclaimed for defamation. In December 2025, the court dismissed most of those counterclaims, finding Lilly’s characterizations of Premier as an “illegal actor” and its description of the pen-cracking practice “substantially true” based on Premier’s own admissions. One narrow defamation question survived: whether Lilly’s statement that Premier “puts patients’ lives at risk” was accurate.13GovInfo. Eli Lilly and Co. v. Premier Weight Loss
Lilly’s Suits Against Telehealth Sellers
On April 23, 2025, Lilly opened a second front, filing four suits in California federal courts against telehealth platforms selling compounded tirzepatide online.14NPR. Eli Lilly Sues Companies Selling Alternative Versions of Its Weight-Loss Drug
- Mochi Health (N.D. Cal., 25-cv-3534): switching patients to compounded formulations containing unapproved additives like niacinamide, manipulating dosages, and improperly controlling affiliated medical groups’ prescribing.
- Fella Health and its subsidiary Delilah (N.D. Cal., 25-cv-3535): selling tirzepatide in an unapproved pill form and falsely claiming it is superior to Lilly’s injectable versions.
- Henry Meds (N.D. Cal., 25-cv-3536): selling an unapproved oral tirzepatide product and improperly referencing Lilly’s approved drugs and clinical trials in marketing.
- Willow Health (C.D. Cal., 25-cv-3570): claiming to have developed the first “cosmetic” GLP-1, though the FDA has never approved tirzepatide for cosmetic weight loss.
The Mochi case is the furthest along. In October 2025, Judge Jacqueline Scott Corley dismissed Lilly’s original complaint for failing to allege Article III standing, but gave leave to amend.15Alliance for Pharmacy Compounding. Eli Lilly v. Mochi Health Dismissed In April 2026, the court largely denied Mochi’s second motion to dismiss the amended complaint, ruling that Lilly had plausibly alleged economic and reputational injury and had viable claims under the California Unfair Competition Law and the Lanham Act. A civil conspiracy claim was dismissed.16Courthouse News Service. Eli Lilly v. Mochi Health Order
Patents Are a Separate Track
One reason Lilly leans on trademark and advertising theories against compounders is that its patent wall does the long-term work on its own. According to the nonprofit I-MAK, Lilly has filed 53 U.S. patent applications on tirzepatide, with 16 patents granted. The primary compound patent (U.S. Patent No. 9,474,780) expires January 5, 2036, and follow-on patents covering devices, formulations, and methods extend protection through at least 2041.17I-MAK. GLP-118GreyB Pharsight. Tirzepatide Patent Expiration
The Injury Side: MDL 3094 and MDL 3163
Patients suing Lilly are consolidated with claims against Novo Nordisk’s semaglutide drugs in two multidistrict litigations before Judge Karen S. Marston in the Eastern District of Pennsylvania.
MDL 3094: Gastrointestinal Injuries
In In re: Glucagon-Like Peptide-1 Receptor Agonists (GLP-1 RAs) Products Liability Litigation, plaintiffs allege that tirzepatide and semaglutide cause gastroparesis, ileus, intestinal obstruction, pancreatitis, gallbladder disease, and related injuries the manufacturers failed to warn about.19U.S. District Court for the Eastern District of Pennsylvania. MDL 3094 More than 4,700 civil actions were on file as of April 2026.20Wagstaff & Cartmell. GLP-1 Multidistrict Litigation MDL 3094
In August 2025, Judge Marston ruled that plaintiffs with gastroparesis claims must have a gastric emptying study in their medical records. Case Management Order No. 30, issued in January 2026, set deadlines for expert disclosures and Daubert briefing on whether plaintiffs’ expert testimony on causation is scientifically reliable enough to reach a jury.20Wagstaff & Cartmell. GLP-1 Multidistrict Litigation MDL 3094 No bellwether trial date has been set; observers expect the first trials no earlier than late 2026, with any mass settlement unlikely before late 2027.21MDL Update. MDL 3094: Glucagon-Like Peptide-1 Receptor Agonists
Lilly has moved to dismiss and to exclude plaintiffs’ experts, arguing that the FDA-approved labeling preempts failure-to-warn claims and that the causation evidence is inadequate. In February 2026, the FDA updated Zepbound’s warning label to add intestinal obstruction and severe constipation, a change that may weaken Lilly’s preemption position on facts arising before the update.22Robert King Law Firm. Zepbound Lawsuit
MDL 3163: Vision Loss (NAION)
A separate MDL, established in December 2025 and also before Judge Marston, covers claims that GLP-1 drugs cause non-arteritic anterior ischemic optic neuropathy, a sudden vision loss caused by reduced blood flow to the optic nerve. MDL 3163 is in early consolidation and discovery.23U.S. District Court for the Eastern District of Pennsylvania. MDL 3163
Where Things Stand in 2026
Almost every case here is still live. Lilly’s suits against Empower and the telehealth defendants have cleared enough motion practice to move into discovery, with the Mochi ruling in April 2026 signaling that similar Lanham Act theories will likely survive early dismissal. The Fifth Circuit could still reshape the compounding landscape if it reverses Judge Pittman in the OFA appeal, but for now the FDA’s shortage determination controls, and continued production of tirzepatide by compounders carries direct legal exposure. On the injury side, MDL 3094 is moving toward expert challenges and possible bellwether trials, while MDL 3163 is just beginning to build.