Eli Lilly has issued an urgent warning against knockoff versions of its weight-loss drugs Mounjaro and Zepbound, citing critical safety issues. The company found significant levels of an impurity in compounded copycats of tirzepatide, the active ingredient in those drugs. The impurity results from a chemical reaction between tirzepatide and vitamin B12, which some compounders add to their products.
The risks to patients are unknown because tirzepatide has never been studied in combination with B12, and compounders are not required to monitor or report adverse events. ' Compounded medications claim to be customized to meet a specific need that cannot be addressed by FDA-approved, commercially available drugs. However, the FDA does not review compounded drugs for safety or quality, raising the risk of improper dosages and contamination.
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.
Although the FDA and a federal court have confirmed that mass-compounding of tirzepatide must stop, some entities continue to do it, claiming to offer 'personalized' versions by adding untested additives like B12. The FDA said last month it would take decisive steps to restrict the sale of non-FDA-approved compounded weight-loss drugs to safeguard consumers. Compounded GLP-1 drugs became popular in the last few years as drugs like tirzepatide and semaglutide have faced shortages.
They are often much cheaper than traditional GLP-1s, costing $130 to $450 per month compared to upwards of $1,000 for classic versions.
Although the FDA and a federal court have confirmed that mass-compounding of tirzepatide must stop, some entities continue to do it, claiming to offer “personalized” versions by adding untested additives, such as B12, to compounded tirzepatide.