Lilly warns about counterfeit and compounded tirzepatide, files new lawsuits

On June 20, 2024, Eli Lilly published an open letter warning about counterfeit and compounded versions of its tirzepatide medicines, Mounjaro and Zepbound, and said it is filing several legal actions against sellers of unapproved compounded products ^[1][2].

The letter says Lilly never sells Mounjaro or Zepbound on social media, and that any offer to buy them there is unlawful. Such products are either fake or resold by an individual who obtained them another way, according to the letter ^[1]. Lilly also says it does not supply tirzepatide, the active ingredient, to compounding pharmacies, med-spas, wellness centers, online retailers or other manufacturers, and that it does not know where those sellers get their ingredient ^[1].

Lilly says testing of products advertised as tirzepatide found safety, sterility and efficacy problems: bacteria, high impurity levels, a pink rather than colorless solution, a completely different chemical structure than its FDA-approved medicines, and in at least one case a product that was nothing more than sugar alcohol ^[1][2].

What the letter says about fakes and compounding

The company says Mounjaro and Zepbound are the only FDA-approved tirzepatide medicines, and that products marketed simply as "tirzepatide" were not made, studied or sold by Lilly and are not FDA-approved ^[1]. Counterfeit products designed to look like Lilly's pens may contain no medicine, the wrong medicine, incorrect dosages or multiple medicines mixed together, which the letter says could result in serious harm ^[1][2].

Lilly cites the National Association of Boards of Pharmacy, which it says has identified thousands of websites promoting illegal sales of GLP-1 agonists and has said illegal actors sell "substandard and falsified versions" of these products ^[1]. The letter also cites FDA statements that "compounded drugs pose a higher risk to patients than FDA-approved drugs" and that unnecessary use of compounded drugs "exposes patients to potentially serious health risks" ^[1][2].

Lilly notes FDA has approved tirzepatide only as an under-the-skin injection, and that no regulator has evaluated the safety or effectiveness of the oral, under-the-tongue or nasal versions some online pharmacies advertise ^[1][2].

Lilly also published identifiers for genuine pens: a purple injection button, a tri-lobular gray base cap, and the script Lilly logo in black ink on Mounjaro and red ink on Zepbound ^[1].

Legal actions and Australia's ban

Lilly says it is filing several lawsuits against med-spas, wellness centers and other entities. In those actions, Lilly alleges the defendants misleadingly called their products Mounjaro or Zepbound, cited Lilly's clinical trial results as if the defendants' compounded drugs had been part of those trials, and referred to FDA approvals for Mounjaro and Zepbound as if the compounded drugs themselves were FDA-approved ^[2]. The exact number of new lawsuits has not been disclosed ^[2].

The new filings follow cases Lilly brought in September and October 2023 and a May 2024 settlement with Totality Medispa that required a monetary payment and barred certain conduct; Lilly says it reached similar settlements with other med-spas and wellness centers ^[2]. No response from the compounding pharmacies or med-spas named in the new actions has been reported.

The letter also notes that on May 21, 2024, the Australian government announced a complete ban on compounded tirzepatide and other compounded diabetes and weight loss medicines, citing increasing reports of patients harmed by incretin medications, including the hospitalization of a patient in Australia ^[1]. Australia's Minister for Health, Mark Butler, said: "This action will protect Australians from harm and save lives" ^[1].

Why it matters for patients

Compounded drugs are not FDA-approved and do not carry the same safety, quality and efficacy protections as approved medicines, according to FDA statements cited in the letter ^[1][2]. If a product is a capsule, a spray or a drop under the tongue, no regulator has evaluated it for safety or effectiveness, because FDA has approved tirzepatide only as an injection under the skin ^[1][2].

Both medicines are approved only for adults 18 and older. Mounjaro is for type 2 diabetes; Zepbound is for adults with obesity, or with excess weight plus weight-related medical problems, used with a reduced-calorie diet and increased physical activity. Neither is approved for cosmetic weight loss, Lilly says ^[1][2].

Lilly says anyone concerned they received or used a counterfeit, fake or otherwise unsafe product should contact a healthcare provider or seek medical attention, and can report the product to local law enforcement or a state board of pharmacy ^[1].

Important details are not in the letter: Lilly did not say how many products it tested, where the testing was done, or which products were involved. Independent data on how often compounded tirzepatide contains contamination has not been reported.

What happens next

Lilly says it will continue to pursue legal remedies against those who falsely claim their products are Mounjaro, Zepbound or "FDA-approved" tirzepatide, and that it supports regulators and law enforcement acting against sellers of unsafe or fake products ^[1]. No court dates or timelines for the newly announced lawsuits have been disclosed ^[2].