Tirzepatide: A Dual Incretin Agonist in Human Trials

Tirzepatide is a 39-amino-acid synthetic peptide, molecular formula C225H348N48O68, that activates both the glucose-dependent insulinotropic polypeptide receptor and the GLP-1 receptor. Its structure is built on the GIP sequence with a C20 fatty di-acid moiety that extends its duration of action to once-weekly dosing. A 2018 discovery paper by Coskun and colleagues characterised that dual-receptor activity in vitro and in diet-induced obese mice.

The human trial record is unusually large. In SURPASS-2, a 40-week phase 3 trial in 1,879 adults with type 2 diabetes, the trial compared tirzepatide at three doses against semaglutide and reported greater mean reductions in glycated haemoglobin and body weight across all three. In SURMOUNT-1, a 72-week phase 3 trial in 2,539 adults with obesity, the trial reported mean weight reductions of 15.0%, 19.5%, and 20.9% at the 5, 10, and 15 mg doses.

One point distinguishes tirzepatide from the rest of this library. It is an approved medicine, marketed as Mounjaro for type 2 diabetes and Zepbound for weight management. The compound Peptheos supplies is a research reagent. It is not the branded product and is not a substitute for it. The trial figures above describe what the studies measured in enrolled participants; they are not statements about any individual.

Supplied for laboratory research use only.