Tirzepatide is a glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) receptor agonist that has been approved by the Food and Drug Administration (FDA) for the treatment of type 2 diabetes. This synthetic polypeptide demonstrates the ability to improve glycemic control in patients and has even shown efficacy in weight loss, making it a potential therapeutic for obesity.

As a glucagon-like peptide-1 (GLP-1) receptor agonist, tizepatide helps regulate blood sugar levels by reducing food intake, increasing satiety, delaying gastric emptying, promoting insulin release, and inhibiting glucagon secretion. However, during its manufacture and storage, impurities can form, potentially affecting the drug’s safety, efficacy, and stability.

Often with therapeutic peptides such as tirzepitide, impurities are peptide-based, structurally similar to semaglutide but may include deletions, additions, D-isomer shifts, or oxidation. D-isomer impurities, for example, can:

• Reduce bioactivity by weakening receptor binding
• Alter pharmacokinetics, affecting absorption and metabolism
• Trigger immunogenicity risks