US drugmaker Eli Lilly has issued a public warning about potential health risks from compounded weight-loss drugs containing vitamin B12 and the active ingredient in its medication, Zepbound. The company stated on Thursday that a previously unidentified impurity, arising during preparation, could pose dangers to consumers.
This alert marks the latest move in Lilly's ongoing efforts against drug compounders, which it accuses of marketing illicit versions of Zepbound and its diabetes treatment, Mounjaro. Both drugs share the same key ingredient, tirzepatide. Lilly has initiated legal proceedings against various compounders, wellness centres, and other entities for selling products claiming to contain tirzepatide.
Conversely, compounders maintain their offerings are legitimate under a specific federal law. This provision permits compounding when patients require tailored medications due to medical concerns, such as the inclusion of vitamins or dosages not available in branded products.
open image in galleryLilly's testing of products obtained from compounding pharmacies, medspas and telehealth networks found "significant levels of an impurity that results from a chemical reaction between tirzepatide and B12," according to the letter and a scientific manuscript on the testing process shared with Reuters.
The impurity was identified in all ten samples tested by Lilly, the company said.
"Nothing is known about its short- or long-term effects in humans, the potential impact on the drug's interaction with the GLP-1 and GIP receptors, toxicity, immune reactions, or how it is absorbed, distributed, metabolized, and eliminated," said the letter, which was posted on the company's website.
"FDA (the U.S. Food and Drug Administration) warns that compounded products can be risky for patients because they are not reviewed for safety, effectiveness, or quality. Adding a reactive substance like vitamin B12 without clinical testing or FDA review introduces additional unknown risks," said David Hyman, Lilly's chief medical officer.
open image in galleryLilly said it notified the FDA of its findings and called for a nationwide recall of products containing both ingredients.
The FDA in September issued warning letters to 30 telehealth companies for making false or misleading claims about compounded versions of weight-loss drugs.
The agency also threatened action against "illegal copycat drugs" after telehealth company Hims & Hers Health said in February it would begin selling a compounded version of Novo Nordisk's Wegovy pill.
Hims quickly backed away from its compounded pill and announced plans this week to sell Novo's Wegovy and Ozempic on its platform.
