What is tirzepatide, and how is its mechanism different from semaglutide?

Tirzepatide (sold as Mounjaro for type 2 diabetes and Zepbound for weight management in Canada) is a "dual agonist". It acts on two gut hormone receptors, GLP-1 and GIP, instead of just one like semaglutide. The added GIP pathway is thought to be part of why tirzepatide has shown somewhat greater average weight loss in clinical trials compared to semaglutide, though individual response varies a lot person to person. References: https://obesitycanada.ca/healthcare-professionals/adult-clinical-practice-guideline/