GIP is a hormone, not a drug
First, the disambiguation: GIP stands for glucose-dependent insulinotropic polypeptide (an older name is gastric inhibitory polypeptide). It’s a natural hormone your gut releases after eating — not a medication. GIP is one of the two main incretin hormones, the signals that tell the pancreas to release insulin in response to a meal. The other incretin is GLP-1. They’re partners: both are released after food, and both help keep post-meal blood sugar in check.
Why GIP matters in the GLP-1 conversation
For years, GLP-1 got most of the attention while GIP sat in the background. That changed with tirzepatide (Mounjaro, Zepbound), which is a dual agonist — a single molecule that activates both the GIP and GLP-1 receptors at the same time. Adding the GIP target is one reason tirzepatide is discussed as a distinct step from GLP-1-only drugs. GIP’s exact contribution is still being studied, and researchers don’t fully agree on every detail of how it aids weight and blood-sugar control — but its inclusion is central to why “GIP/GLP-1” appears in these drugs’ descriptions.
What to keep in mind
You won’t be prescribed “GIP” on its own. Where it shows up is inside combination molecules — most notably tirzepatide — and in the newer triple agonists that target GIP alongside GLP-1 and glucagon. If a medication’s description mentions GIP, it’s telling you the drug leans on this second incretin in addition to GLP-1. For how any specific drug uses it, talk to your prescriber and see the GLP-1 overview.