29 October 2026
What is tirzepatide?
Tirzepatide is a synthetic peptide studied for its ability to activate two receptors at once. Pep Pantry sells it as a freeze-dried powder for laboratory research.
Two receptors
Tirzepatide is described as acting on the GIP receptor and the GLP-1 receptor. A receptor is a protein on the surface of a cell that responds to a particular signal molecule, and each of these two is named after the natural hormone that normally binds to it.
A compound that switches a receptor on is called an agonist. Because tirzepatide acts on two, it is called a dual agonist.
How it differs from retatrutide
Retatrutide acts on the same two receptors and on a third, the glucagon receptor. In research papers the two compounds are therefore described as dual and triple agonists. That one extra receptor is the main difference people mean when they compare them. Our post on retatrutide covers the other side.
Why researchers study receptor agonists
Receptors like these sit at the start of long chains of signals inside cells. A compound that activates a receptor in a controlled way lets a laboratory watch what the cell does next, for example in cultured cells where the response can be measured. Our post on the three receptors explains how that works in practice.
Strengths and kits
On the site, tirzepatide comes in several strengths. The strength is the amount of the compound in each vial, in milligrams, and every kit is ten vials of one strength. The product page lists what is available.
Handling in the lab
It is supplied as a dry powder, dissolved in a diluent before use, and kept cold afterwards. Our posts on reconstitution and on storing vials describe the usual routine.
Reading research papers
When you read papers on tirzepatide, check which receptor each result refers to, because activity at the GIP receptor and at the GLP-1 receptor is reported separately. Also check the system the work was done in, such as cultured cells, since a result in one system does not carry over automatically to another.
Research use only
Pep Pantry products are sold for laboratory research by adults. They are not for human or veterinary use. This article describes the compound for laboratory readers only.