Lilly Warns on Compounded Zepbound After Finding Impurity (1)

Eli Lilly & Co. warned that the active ingredient in its weight-loss blockbuster Zepbound could pose a risk to patients when mixed with vitamin B12, a combination sold by US drug compounders.

Lilly tested compounded products and found “significant levels of an impurity” resulting from a chemical reaction between the vitamin and the active ingredient, tirzepatide, it said Thursday.

“People receiving tirzepatide-B12 products from compounders, telehealth companies, medspas, or anyone else should be aware that they may be using a potentially dangerous product with unknown risks,” the drugmaker said in an open letter, citing possible toxicity and immune reactions. ...