Regulators warn on compounded GLP‑1s
Regulatory heat is rising: Eli Lilly issued an open letter warning of potential safety risks and impurities in compounded tirzepatide with vitamin B12, and Colorado lawmakers are targeting misleading claims around compounded GLP‑1 products. The moves underline mounting concern about nonstandard, unregulated formulations hitting the market. Eli Lilly Releases Open Letter Warning of Potential Safety Risks for Compounded Tirzepatide Plus Vitamin B12 Colorado Bill Targets Misleading Weight Loss Drugs & Compounded Medications
Lilly’s internal testing uncovered significant levels of a chemical impurity formed when tirzepatide was combined with methylcobalamin, hydroxocobalamin or cyanocobalamin, the company said in an open letter. ebs.publicnow.com A PharmExec briefing reported that testing of samples obtained from compounding pharmacies, medspas and telehealth networks showed significant impurity levels in all ten products evaluated. pharmexec.com The company has notified the U.S. Food and Drug Administration and has urged the agency to order a nationwide recall of compounded tirzepatide products that include B12 or other untested additives, according to reporting and Lilly statements. biopharmadive.com Colorado’s SB26‑066 would require compounded weight‑loss medications to be made from FDA‑approved bulk substances, manufactured in FDA‑compliant facilities inspected within the prior two years, and to carry labels listing all ingredients and country of origin, the bill text shows. leg.colorado.gov SB26‑066, sponsored by Senators Iman Jodeh and John Carson, would allow the state board of pharmacy to fine violators up to $1,000 per dose and gives the attorney general authority to enforce deceptive‑advertising provisions under the Colorado Consumer Protection Act. leg.colorado.gov Federal enforcement has already been tightening: the FDA announced a “green list” in early September 2025 to restrict imported compounding ingredients for GLP‑1s and has stressed that temporary compounding flexibilities used during 2023–24 shortages were rescinded. pharmexec.com
