Tirzepatide is a 39-residue synthetic peptide that engages two incretin pathways simultaneously: the GLP-1 receptor and the GIP receptor. Co-activation produces effects on insulin secretion, gastric emptying, and adipose signaling that single-receptor agonists do not replicate. In published in-vitro and animal models, the compound shows extended plasma half-life relative to native incretins, attributed to a C-20 fatty diacid moiety that promotes albumin binding.