tirzepatide + cobalamin

Tirzepatide + cobalamin is a compounded fixed-dose combination of tirzepatide, a synthetic dual glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) receptor agonist, and cobalamin (vitamin B12). This combination is prepared by various compounding pharmacies and telehealth platforms as a weekly subcutaneous injection primarily for weight management (obesity and overweight) and type 2 diabetes. The addition of cobalamin is intended to support cellular energy metabolism and mitigate common side effects of tirzepatide, such as fatigue and nausea. However, this combination is not FDA-approved, and Eli Lilly (the originator of tirzepatide) has issued public warnings regarding the safety of mixing tirzepatide with vitamin B12, citing the formation of a previously uncharacterized tirzepatide-cobalamin adduct impurity with unknown clinical effects.