Eli Lilly Flags Impurity in Tirzepatide-B12 Mix, Shares Drop 1%
Eli Lilly found significant impurity levels in compounded tirzepatide–B12 formulations, warning these could cause toxicity or immune reactions and noting bacterial contamination and elevated endotoxin risks. Shares slipped about 1% after the warning spurred calls for an FDA recall of unapproved compounded versions.
1. Safety Concerns in Compounded Formulations
Testing of compounded tirzepatide–B12 products revealed significant levels of an impurity formed by a chemical reaction between tirzepatide and vitamin B12, raising concerns over potential toxicity, immune responses, bacterial contamination and elevated endotoxin levels in these unapproved mixtures.
2. Stock Reaction and Market Response
Shares of the company fell approximately 1% in early trading as the safety warning prompted investor concern over potential liability and demand disruptions for its Zepbound weight-loss treatment.
3. Regulatory Pressure Ahead
Lilly has urged the FDA to recall all compounded tirzepatide products containing additives such as B12, glycine, pyridoxine, niacinamide and carnitine, citing their lack of clinical testing and potential health risks and signaling possible tighter oversight of compounded GLP-1 drugs.