The peptide that turned the metabolic-research world on its head — and the bridge between the old GLP-1 drugs and the new triple agonists.
If you want to understand why metabolic peptides became the most talked-about category in medicine, tirzepatide is the story’s turning point. It took a well-established idea and added a second lever — and the results reset expectations across the field.
What it is
Tirzepatide is a dual agonist: a single molecule that activates two different gut-hormone receptors at once, GLP-1 and GIP. The earlier generation of incretin compounds — semaglutide being the famous one — work on GLP-1 alone. Tirzepatide’s trick is engaging GIP as well, and the two pathways appear to complement each other.
Why it matters in the research
GLP-1 and GIP are both “incretin” hormones — signals your gut releases after eating that influence insulin, appetite and how the body handles energy. Activating both simultaneously produced effects in the published trial programme that were notably larger than GLP-1 alone, which is what put tirzepatide at the centre of metabolic research.
It’s best understood as the middle step: GLP-1 mono-agonists, then dual agonists like tirzepatide, then the triple agonists that followed.
Where it sits
That progression is the most useful way to place it. Retatrutide takes the idea one step further again by adding a third receptor (glucagon) — which is why the two are so often compared in the literature. If tirzepatide proved the dual-agonist concept, retatrutide is the research world testing how far the idea can go.
Handling in the lab
Supplied lyophilised, reconstituted with bacteriostatic water and refrigerated once mixed. Every batch we hold is ≥99% HPLC purity with independent Janoshik verification — the certificate is on the product page.
In the catalogue
Tirzepatide
Stocked in our UK warehouse at ≥99% HPLC purity, Janoshik independently tested.

