Triple agonist peptides retatrutide GLP-3 research Durham Peptides Canada Few peptide categories have moved as fast as triple agonist metabolic peptides. In less than a decade, the field has progressed from single-receptor compounds (semaglutide) to dual-receptor compounds (tirzepatide) to the first triple-receptor agonist — retatrutide — currently in advanced clinical trials. Each generation has generated more research attention than the last, and the terminology has evolved