Eli Lilly warns about dangers of fake and counterfeit Mounjaro, Zepbound

Pharmaceutical company Eli Lilly issued a warning in an open letter on Thursday about the dangers of fake and compounded versions of its diabetes and weight loss medications Mounjaro and Zepbound.

The company also announced new lawsuits against wellness centers and medical spas advertising these drugs.

Eli Lilly's main competitor, Novo Nordisk, which sells Ozempic and Wegovy, has also filed lawsuits against med spas purportedly selling knockoff versions.

Both companies say the extraordinary demand for these drugs has led to shortages, which has in turn prompted black and grey market sales of other versions of their products that may pose a health risk to consumers.

In its Thursday open letter, Eli Lilly issued a major warning to consumers, saying the company is "deeply" concerned about the proliferation of online sales of fake versions of its products, and that people should never put products labeled "research purposes only" or "not for human consumption" into their bodies.

Eli Lilly says they never sell genuine Mounjaro or Zepbound on social media.

Fake drugs aside, Eli Lilly is also raising concerns about compounding pharmacies. These are technically legal amid an ongoing drug shortage, but the Food and Drug Administration has raised concerns about bad actors making substandard products.

Eli Lilly says that the company has done testing of compounded versions of their drug, and they have observed safety, sterility and efficacy problems. Some of the products have bacteria, high impurities, different colors or a completely different chemical structure than the company's FDA-approved medicine. In at least one instance, the product was nothing more than sugar alcohol, Eli Lilly said.

In addition to these warnings about fake and compounded products, Lilly reiterated the company's prior stance that these drugs should not be prescribed or used for "cosmetic" weight loss. The company said they should be for people living with diabetes and/or obesity, or who are overweight with other related medical conditions.